Method and apparatus for processing thin metal layers

• US 7,115,503 B2
• Filed: 10/09/2001
• Issued: 10/03/2006
• Est. Priority Date: 10/10/2000
• Status: Expired due to Fees

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Im, James S.
• Primary Examiner(s): GURLEY, LYNNE ANN
• Application Number:
  US10/129,159
• Publication Number:
  US 20030029212A1
• Time in Patent Office: 1,820 Days
• Field of Search: 438660-662, 438686-688, 438/795, 438798-799, 438/940, 438/955
• US Class Current: 438/660
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 21/76894 using a laser, e.g. laser cutting, laser direct writing, laser repair
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: Y10S 438/94 Laser ablative material removal
• CPC Class Codes: Y10S 438/955 Melt-back

Abstract

A method and apparatus for processing a thin metal layer on a substrate to control the grain size, grain shape, and grain boundary location and orientation in the metal layer by irradiating the metal layer with a first excimer laser pulse having an intensity pattern defined by a mask to have shadow regions and beamlets. Each region of the metal layer overlapped by a beamlet is melted throughout its entire thickness, and each region of the metal layer overlapped by a shadow region remains at least partially unmelted. Each at least partially unmelted region adjoins adjacent melted regions. After irradiation by the first excimer laser pulse, the melted regions of the metal layer are pemitted to resolidify. During resolidification, the at least partially unmelted regions seed growth of grains in adjoining melted regions to produce larger grains. After completion of resolidification of the melted regions following irradiation by the first excimer laser pulse, the metal layer is irradiated by a second excimer laser pulse having a shifted intensity pattern so that the shadow regions overlap regions of the metal layer having fewer and larger grains. Each region of the metal layer overlapped by one of the shifted beamlets is melted throughout its entire thickness, while each region of the metal layer overlapped by one of the shifted shadow regions remains at least partially unmelted. During resolidification of the melted regions after irradiation by the second radiation beam pulse, the larger grains in the at least partially unmelted regions seed growth of even larger grains in adjoining melted regions. The irradiation, resolidification and re-irradiation of the metal layer may be repeated, as needed, until a desired grain structure is obtained in the metal layer.

Claims

1. A method for processing a thin metal layer disposed on a substrate comprising the steps of:

(a) irradiating at least a portion of the metal layer with a first radiation beam pulse having an intensity pattern that includes at least one beamlet and at least one shadow region, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one adjacent melted region, wherein the intensity pattern of each radiation beam pulse is defined by a mask through which the radiation beam pulse passes;

(b) permitting each melted region of the at least a portion of the metal layer irradiated by the first radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region;

(c) irradiating at least a portion of the metal layer with a further radiation beam pulse having the same intensity pattern as the previous radiation beam pulse, wherein the previous radiation beam pulse is the first radiation beam pulse of step (a), but where the at least one beamlet and the at least one shadow region thereof are shifted with respect to the at least a portion of the metal layer, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one melted region, wherein the intensity pattern of the further radiation beam pulse is shifted with respect to the at least a portion of the metal layer by shifting the substrate having the metal layer;

(d) permitting each melted region of the at least a portion of the metal layer irradiated by the further radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region, the further radiation beam pulse being the previous radiation beam pulse for further processing; and

(e) repeating steps (c) and (d) in combination, if needed, with the further radiation beam pulse in each step becoming the previous radiation beam pulse in the next step, until a desired grain structure is obtained in the at least a portion of the metal layer.

2. A method for processing a thin metal layer disposed on a substrate comprising the steps of:

(a) irradiating at least a portion of the metal layer with a first radiation beam pulse having an intensity pattern that includes at least one beamlet and at least one shadow region, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one adjacent melted region, wherein the intensity pattern of each radiation beam pulse is defined by a mask through which the radiation beam pulse passes;

(b) permitting each melted region of the at least a portion of the metal layer irradiated by the first radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region;

(c) irradiating at least a portion of the metal layer with a further radiation beam pulse having the same intensity pattern as the previous radiation beam pulse, wherein the previous radiation beam pulse is the first radiation beam pulse of step (a), but where the at least one beamlet and the at least one shadow region thereof are shifted with respect to the at least a portion of the metal layer, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one melted region, wherein the intensity pattern of the further radiation beam pulse is shifted with respect to the at least a portion of the metal layer by shifting the mask;

(d) permitting each melted region of the at least a portion of the metal layer irradiated by the further radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region, the further radiation beam pulse being the previous radiation beam pulse for further processing; and

(e) repeating steps (c) and (d) in combination, if needed, with the further radiation beam pulse in each step becoming the previous radiation beam pulse in the next step, until a desired grain structure is obtained in the at least a portion of the metal layer.

3. A method for processing a thin metal layer disposed on a substrate comprising the steps of:

(a) irradiating at least a portion of the metal layer with a first radiation beam pulse having an intensity pattern that includes at least one beamlet and at least one shadow region, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one adjacent melted region, wherein the metal layer comprises at least one metal layer strip each having a predefined contour and the intensity pattern of the first radiation beam pulse has at least one string of multiple, relatively small, regularly spaced-apart, dot-like shadow regions, each string of shadow regions conforming to a respective predefined contour and overlapping a respective one of the at least one metal layer strip having the same predefined contour;

(b) permitting each melted region of the at least a portion of the metal layer irradiated by the first radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region,

(c) irradiating at least a portion of the metal layer with a further radiation beam pulse having the same intensity pattern as the previous radiation beam pulse, wherein the previous radiation beam pulse is the first radiation beam pulse of step (a), but where the at least one beamlet and the at least one shadow region thereof are shifted with respect to the at least a portion of the metal layer, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one melted region;

(d) permitting each melted region of the at least a portion of the metal layer irradiated by the further radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region, the further radiation beam pulse being the previous radiation beam pulse for further processing; and

(e) repeating steps (c) and (d) in combination, if needed, with the further radiation beam pulse in each step becoming the previous radiation beam pulse in the next step, until a desired grain structure is obtained in the at least a portion of the metal layer.

4. The method of claim 3, wherein the desired grain structure of each one of the at least one metal layer strip comprises a plurality of single grain regions separated by respective grain boundaries, each grain boundary being approximately perpendicular to the metal layer strip at the location of the grain boundary.

5. A method for processing a thin metal layer disposed on a substrate comprising the steps of:

(a) irradiating at least a portion of the metal layer with a first radiation beam pulse having an intensity pattern that includes at least one beamlet and at least one shadow region, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one adjacent melted region, wherein the metal layer comprises at least one metal layer strip each having a respective predefined contour, and the intensity pattern of the first radiation beam pulse has at least one relatively narrow, strip-like shadow region, each one of the at least one strip-like shadow region having a respective one of the predefined contour of each one of the at least one metal layer strip, and overlapping a respective one of the at least one metal layer strip having the same predefined contour;

(b) permitting each melted region of the at least a portion of the metal layer irradiated by the first radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region;

(c) irradiating at least a portion of the metal layer with a further radiation beam pulse having the same intensity pattern as the previous radiation beam pulse, wherein the previous radiation beam pulse is the first radiation beam pulse of step (a), but where the at least one beamlet and the at least one shadow region thereof are shifted with respect to the at least a portion of the metal layer, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one melted region;

(d) permitting each melted region of the at least a portion of the metal layer irradiated by the further radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region, the further radiation beam pulse being the previous radiation beam pulse for further processing; and

(e) repeating steps (c) and (d) in combination, if needed, with the further radiation beam pulse in each step becoming the previous radiation beam pulse in the next step, until a desired grain structure is obtained in the at least a portion of the metal layer.

6. A method for processing a thin metal layer disposed on a substrate comprising the steps of:

(a) irradiating at least a portion of the metal layer with a first radiation beam pulse having an intensity pattern that includes at least one beamlet and at least one shadow region, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one adjacent melted region, wherein the intensity pattern of each radiation beam pulse includes a multiplicity of relatively small, dot-like shadow regions disposed in a regular array, the spacings between adjacent shadow regions being such that grains growing from each at least partially unmelted region of the at least a portion of the metal layer abut grains growing from adjacent at least partially unmelted regions;

(b) permitting each melted region of the at least a portion of the metal layer irradiated by the first radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region;

(c) irradiating at least a portion of the metal layer with a further radiation beam pulse having the same intensity pattern as the previous radiation beam pulse, wherein the previous radiation beam pulse is the first radiation beam pulse of step (a), but where the at least one beamlet and the at least one shadow region thereof are shifted with respect to the at least a portion of the metal layer, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one melted region;

(d) permitting each melted region of the at least a portion of the metal layer irradiated by the further radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region, the further radiation beam pulse being the previous radiation beam pulse for further processing; and

(e) repeating steps (c) and (d) in combination, if needed, with the further radiation beam pulse in each step becoming the previous radiation beam pulse in the next step, until a desired grain structure is obtained in the at least a portion of the metal layer.

7. The method of claim 6, wherein the multiplicity of relatively small, dot-like shadow regions are disposed at respective intersections of regular spaced-apart, mutually-perpendicular diagonal lines, and wherein the desired grain structure comprises approximately square-shaped single grain regions.

8. A method for processing a thin metal layer disposed on a substrate comprising the steps of:

(a) irradiating at least a portion of the metal layer with a first radiation beam pulse having an intensity pattern that includes at least one beamlet and at least one shadow region, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one adjacent melted region, wherein the intensity pattern of each radiation beam pulse comprises a plurality of regularly spaced-apart, elongated shadow regions and a plurality of regularly spaced-apart, elongated beamlets, each beamlet being positioned in between and adjoining respective adjacent shadow regions, each region of the at least a portion of the metal layer overlapped by a respective one of the beamlets being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the shadow regions remaining at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions;

(b) permitting each melted region of the at least a portion of the metal layer irradiated by the first radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region;

(c) irradiating at least a portion of the metal layer with a further radiation beam pulse having the same intensity pattern as the previous radiation beam pulse, wherein the previous radiation beam pulse is the first radiation beam pulse of step (a), but where the at least one beamlet and the at least one shadow region thereof are shifted with respect to the at least a portion of the metal layer in a direction perpendicular to the elongated shadow regions and beamlets of the intensity pattern of the previous radiation beam pulse, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted beamlet being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the at least one shifted shadow region remaining at least partially unmelted, each at least partially unmelted region adjoining at least one melted region;

(d) permitting each melted region of the at least a portion of the metal layer irradiated by the further radiation beam pulse to resolidify, wherein during resolidification of each melted region, grains grow therein from each one of the at least one adjoining at least partially unmelted region, the further radiation beam pulse being the previous radiation beam pulse for further processing; and

(e) repeating steps (c) and (d) in combination, if needed, with the further radiation beam pulse in each step becoming the previous radiation beam pulse in the next step, until a desired grain structure is obtained in the at least a portion of the metal layer.

9. The method of claim 8, wherein the beamlets are each in the shape of repeating chevrons, and adjacent repeating chevron-shaped beamlets are staggered with respect to one another such that upward pointing apexes of each one of the repeating chevron-shaped beamlets are aligned with respective downward pointing apexes of adjacent repeating chevron-shaped beamlets, and downward pointing apexes of each one of the repeating chevron-shaped beamlets are aligned with respective upward pointing apexes of adjacent repeating chevron-shaped beamlets, and wherein the desired grain structure comprises adjoining single grain regions having a generally hexagonal shape.

10. A method for processing a thin metal layer disposed on a substrate comprising the steps of:

(a) irradiating at least a portion of the metal layer with a first radiation beam pulse having an intensity pattern that includes a plurality of regularly spaced-apart, relatively narrow, linear, stripe-like shadow regions, and a plurality of regularly spaced-apart, relatively wide, linear, stripe-like beamlets, each one of the beamlets being positioned in between and adjoining respective adjacent shadow regions, each region of the at least a portion of the metal layer overlapped by a respective one of the beamlets being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the shadow regions remaining at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions;

(b) permitting each melted region of the at least a portion of the metal layer to resolidify after irradiation by the first radiation beam pulse, wherein during resolidification of each melted region, grains grow therein from adjoining at least partially unmelted regions in opposite directions towards one another, and abut one another along a respective one of a plurality of first grain abutment boundaries;

(c) irradiating the at least a portion of the metal layer with a second radiation beam pulse having the same intensity pattern as the first radiation beam pulse, but where the shadow regions and beamlets thereof are shifted with respect to the at least a portion of the metal layer in a direction perpendicular to the beamlets and shadow regions by a distance at least equal to the width of the shadow regions of the intensity pattern, each region of the at least a portion of the metal layer overlapped by a respective one of the shifted beamlets being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the shifted shadow regions remaining at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions; and

(d) permitting each melted region of the at least a portion of the metal layer to resolidify after irradiation by the second radiation beam pulse, wherein during resolidification of each melted region, respective single grains grow therein from adjoining at least partially unmelted regions in opposite directions towards one another, and abut one another along a respective one of a plurality second grain abutment boundaries, and wherein upon completion of resolidification of each melted region after irradiation by the second radiation beam pulse, the at least a portion of the metal layer has a grain structure comprising relatively long single grains extending between respective adjacent second grain abutment boundaries and having lateral grain boundaries approximately perpendicular to the second grain abutment boundaries.

11. The method of claim 10, wherein each of the first and second radiation beam pulses is a laser beam pulse.

12. The method of claim 11, wherein each of the first and second radiation beam pulses is an excimer laser beam pulse.

13. The method of claim 11, wherein the respective intensity pattern of the first and second radiation beam pulses are each defined by a mask through which the first and second radiation beam pulses pass, and the shadow regions and beamlets of the intensity pattern of the second radiation beam pulse are shifted with respect to the at least a portion of the metal layer by shifting the substrate having the metal layer.

14. The method of claim 13, wherein the mask is a projection mask.

15. The method of claim 13, wherein the mask is a proximity mask.

16. The method of claim 13, wherein the mask is a contact mask.

17. The method of claim 11, wherein the respective intensity patterns of the first and second radiation beam pulses are defined by a mask through which the first and second radiation beam pulses pass, and the shadow regions and beamlets of the intensity patterns of the first second radiation beam pulse are shifted with respect to the at least a portion of the metal layer by shifting the mask.

18. The method of claim 10, wherein each one of the first and second radiation beam pulses is a electron beam pulse.

19. The method of claim 10, wherein each one of the first and second radiation beam pulses is an ion beam pulse.

20. The method of claim 10, further comprising the steps of:

(e) after resolidification of the melted regions of the least a portion of the metal layer following irradiation by the second radiation beam pulse, rotating the metal layer on the substrate by 90°

with respect to the second grain abutment boundaries;

(f) irradiating the at least a portion of the metal layer with a third radiation beam pulse having an intensity pattern that includes a plurality of regularly spaced-apart, relatively-narrow, linear, stripe-like shadow regions and a plurality of regularly spaced-apart, relatively wide, linear, stripe-like beamlets, each one of the beamlets being positioned in between and adjoining respective adjacent shadow regions, each one of the shadow regions and beamlets being approximately perpendicular to the second grain abutment boundaries, each region of the at least a portion of the metal layer overlapped by a respective one of the beamlets being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the shadow regions remaining at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions;

(g) permitting each melted region of the at least a portion of the metal layer to resolidify after irradiation by the third radiation beam pulse, wherein during resolidification of each melted region, different single grains grow from each at least partially unmelted region into each adjoining melted region, and in each melted region respective single grains grow from adjoining at least partially unmelted regions in opposite directions towards one another, and abut one another along a respective one of a plurality of third grain abutment boundaries, each one of the abutting single grains having a dimension in a direction parallel to the third grain abutment boundaries approximately equal to the distance between adjacent second grain abutment boundaries;

(h) irradiating the at least a portion of the metal layer with a fourth radiation beam pulse having the same intensity pattern as the third radiation beam pulse, but where the shadow regions and beamlets thereof are each shifted with respect to the at least a portion of the metal layer in a direction approximately perpendicular to the third grain abutment boundaries by a distance at least equal to the width of the shadow regions of the intensity pattern, each region of the at least a portion of the metal layer overlapped by a respective one of the shifted beamlets being melted throughout its entire thickness, each region of the at least a portion of the metal layer overlapped by a respective one of the shifted shadow regions remaining at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions; and

(i) permitting each melted region of the at least a portion of the metal layer to resolidify after irradiation by the fourth radiation beam pulse, wherein during resolidification of each melted region, respective single grains grow from each at least partially unmelted region into each adjoining melted region, and in each one of the melted regions, respective single grains grow from adjoining at least partially unmelted regions in opposite directions towards one another, and abut one another at a respective one of a plurality of fourth grain abutment boundaries, and wherein upon completion of resolidification of the melted regions, the at least a portion of the metal layer has a grain structure comprising an array of generally rectangular-shaped single grain regions in respective rows and columns, each generally rectangular-shaped single grain region having a dimension on two opposing sides substantially equal to the distance between adjacent second grain abutment boundaries and having a dimension on the other two opposing sides substantially equal to the distance between adjacent fourth grain abutment boundaries.

21. The method of claim 10, wherein the metal layer is formed of one of an elemental metal, a compound metal and an alloy metal.

22. The method of claim 10, wherein the metal layer is formed of one of aluminum, copper, tungsten, titanium, platinum and gold.

23. The method of claim 10, wherein the metal layer is disposed on a substrate having a diffusion barrier layer.

24. The method of claim 10, wherein the metal layer is formed on the substrate having a diffusion barrier layer formed of one of silicon dioxide, tantalum and a tantalum compound.

25. The method of claim 10, wherein the at least a portion of the metal layer is subdivided into a plurality of sections, and steps (a), (b), (c) and (d) are carried out in combination in each one of the sections, one section at a time.

26. The method of claim 25, wherein the at least a portion of the metal layer is subdivided into contiguous sections, and steps (a), (b), (c) and (d) are carried out in combination in successive contiguous ones of the sections one section at a time, and wherein the irradiation of steps (a) and (b) each overlap a previous contiguous section by a relatively small area.

27. The method of claim 10, wherein the at least a portion of the metal layer is subdivided into a plurality of sections, and steps (a), (b), (c) and (d) are separately carried out one step at a time in each one of the sections, one section at a time.

28. The method of claim 27, wherein the at least a portion of the metal layer is subdivided into contiguous sections, and steps (a), (b), (c) and (d) are separately carried out one step at a time in successive contiguous ones of the sections, one section at a time, and wherein the irradiation of steps (a) and (c) each overlap a previous contiguous section by a relatively small area.

29. A method for processing a thin metal layer disposed on a substrate, the metal layer comprising at least one relatively narrow metal layer strip each having a respective one of at least one predefined contour conforming to a Manhattan geometry, the method comprising the steps of:

(j) irradiating the at least one metal layer strip with a first radiation beam pulse having an intensity pattern that includes a plurality of relatively narrow, linear, stripe-like shadow regions overlapping each one of the at least one metal layer strip at regular intervals along its respective predefined contour and a beamlet overlapping all regions of the at least one metal layer strip not overlapped by one of the shadow regions, each region of the at least one metal layer strip overlapped by the beamlet being melted throughout its entire thickness, each region of the at least one metal layer strip overlapped by a respective one of the shadow regions remaining at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions;

(k) permitting each melted region of the at least one metal layer strip to resolidify after being irradiated by the first radiation beam pulse, wherein during resolidification of each melted region, different single grains grow from each one of the at least partially unmelted regions into each adjoining melted region, and in each melted region respective single grains grow from adjoining at least partially unmelted regions in opposite directions towards one another, and abut one another at a respective one of a plurality of first grain abutment boundaries;

(l) irradiating the at least one metal layer with a second radiation beam pulse having the same intensity pattern as the first radiation beam pulse, but where the shadow regions and the beamlet thereof are shifted such that the shadow regions are shifted along each one of the at least one metal layer strip by a distance greater than the width of the shadow regions of the intensity pattern but less than the distance that would cause the shifted shadow regions to overlap the first grain abutment boundaries, each region of the at least one metal layer strip overlapped by the shifted beamlet being melted throughout its entire thickness, each region of the at least one metal layer strip overlapped by a respective one of the shifted shadow regions remaining at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions; and

(m) permitting each melted region of the at least one metal layer strip to resolidify after being irradiated by the second radiation beam pulse, wherein during resolidification of each melted region, a respective single grain grows from each at least partially unmelted region into each adjoining melted regions, and in each melted region respective single grains grow from adjoining at least partially unmelted regions in opposite directions towards one another, and abut one another at a respective one of a plurality of second grain abutment boundaries, and wherein after completion of resolidification following irradiation by the second radiation beam pulse, each one of the at least one metal layer strip has a grain structure comprising single grain regions extending between respective adjacent second grain abutment boundaries, each second grain abutment boundary being approximately perpendicular to a respective one of the at least one metal layer strip at the location of the second grain abutment boundary.

30. The method of claim 29, wherein each of the first and second radiation beam pulses is a laser beam pulse.

31. The method of claim 29, wherein each of the first and second radiation beam pulses is an excimer laser beam pulse.

32. The method of claim 29, wherein each of the first and second radiation beam pulses is a electron beam pulse.

33. The method of claim 29, wherein each of the first and second radiation beam pulses is a ion beam pulse.

34. The method of claim 29, wherein each of the first and second radiation beam pulses is a laser pulse, and the intensity patterns of the first and second radiation beam pulses are defined by a mask through which the first and second radiation beam pulses pass, the intensity pattern of the second radiation beam pulse being shifted with respect to the at least one metal layer strip by shifting the substrate having the at least one metal layer strip.

35. The method of claim 29, wherein each of the first and second radiation beam pulses is a laser beam pulse, and the respective intensity patterns of the first and second radiation beam pulses are defined by a mask through which the first and second radiation beam pulses pass, the intensity pattern of the second radiation beam pulse being shifted with respect to the at least one metal layer strip by shifting the mask.

36. A method for processing a thin metal layer, the metal layer comprising at least one relatively narrow metal layer strip having at least one segment and a respective predefined contour conforming to a Manhattan geometry, the method comprising the steps of:

(n) irradiating the at least one metal layer strip with a first radiation beam pulse having an intensity pattern that includes a plurality of regularly spaced-apart, relatively narrow, linear, stripe-like shadow regions and a plurality of regularly spaced-apart, relatively wide, linear, stripe-like beamlets, each one of the beamlets being positioned in between and adjoining respective adjacent shadow regions, each segment of the at least one metal layer strip being diagonally oriented with respect to the shadow regions and the beamlets, each region of the at least one metal layer strip overlapped by a respective one of the beamlets being melted throughout its entire thickness, each region of the at least one metal layer strip overlapped by a respective one of the shadow regions remaining at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions;

(o) permitting each melted region of the at least one metal layer strip to resolidify after irradiation by the first radiation beam pulse, wherein during resolidification of each melted region, different single grains grow from each at least partially unmelted region into each adjoining melted region, and in each melted region respective single grains grow from adjoining at least partially unmelted regions in opposite directions towards one another, and abut one another at a respective one of a plurality of first grain abutment boundaries, each one of the first grain abutment boundaries being approximately perpendicular to a respective one of the at least one metal layer strip at the location of the first grain abutment boundary;

(p) irradiating the at least one metal layer strip by a second radiation beam pulse having the same intensity pattern as the first radiation beam pulse, but where the shadow regions and beamlets thereof are shifted with respect to the at least one metal layer strip in a direction perpendicular to the shadow regions and beamlets of the intensity pattern of the first radiation beam pulse by a distance greater than the width of the shadow regions of the intensity pattern but less than the distance that would cause the shifted shadow regions to overlap the first grain abutment boundaries, each region of the at least one metal layer strip overlapped by a respective one of the shifted beamlets being melted throughout its entire thickness, each region of the at least one metal layer strip overlapped by a respective one of the shifted shadow regions remaining at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions; and

d) permitting each melted region of the at least one metal layer strip to resolidify after irradiation by the second radiation beam pulse, wherein during resolidification of each melted region, a respective single grain grows from each at least partially unmelted region into each adjoining melted region, and in each melted region respective single grains grow from adjoining at least partially unmelted regions in opposite directions towards one another, and abut one another at a respective one of a plurality of second grain abutment boundaries, each second grain abutment boundary being approximately perpendicular to a respective one of the at least one metal layer strip at the location of the second grain abutment boundary, and wherein after completion of resolidification following irradiation by the second radiation beam pulse each one of the at least one metal layer strip has a grain structure comprising single grain regions extending between respective adjacent second grain abutment boundaries.

37. A method for processing a thin metal layer disposed on a substrate comprising the steps of:

(q) irradiating at least a portion of the metal layer by a radiation beam pulse having an intensity pattern that includes a stripe-shaped beamlet having a predefined contour and a shadow region that overlaps all regions of the at least a portion of the metal layer not overlapped by the beamlet, a region of the at least a portion of the metal layer overlapped by the beamlet being melted throughout its entire thickness so as to form a melted region having the predefined contour, each region of the at least a portion of the metal layer overlapped by the shadow region remaining at least partially unmelted, the melted region being surrounded by an unmelted region that adjoins the melted region along first and second opposing edges of the melted region;

(r) permitting the melted region to resolidify after irradiation by the radiation beam pulse to form a resolidification region having the predefined contour, wherein during resolidification of the melted region to form the resolidification region, first and second rows of grains grow from the first and second opposing edges of the melted region, respectively, in opposite directions towards one another; and

(s) after the melted region has completely resolidified, patterning the metal layer to form at least one relatively narrow metal layer strip formed from a strip-shaped region having the predefined contour in one of the first and second rows of grains in the resolidification region, the metal layer strip having the predefined contour and single grain regions separated by respective grain boundaries, each grain boundary forming a relatively large angle with respect to the metal layer strip at the location of the grain boundary.

38. The method of claim 37, wherein during resolidification of the melted region, the first and second rows of grains grow in opposite directions towards one another until the first and second rows of grains abut one another along a grain abutment boundary that extends centrally through the resolidified region and that has the predefined contour.

39. The method of claim 37, wherein the radiation beam pulse is a laser beam pulse.

40. The method of claim 39, wherein the laser beam pulse is an excimer laser beam pulse.

41. The method of claim 37, wherein the radiation beam pulse is a electron beam pulse.

42. The method of claim 37, wherein the radiation beam pulse is an ion beam pulse.

43. The method of claim 37, wherein the intensity pattern of the radiation beam pulse is defined by a mask through which the radiation beam pulse passes.

44. The method of claim 43, wherein the mask is a projection mask.

45. The method of claim 43, wherein the mask is a proximity mask.

46. The method of claim 43, wherein the mask is a contact mask.

47. A method for processing a thin metal layer disposed on the substrate comprising the steps of:

(t) dividing for processing purposes at least a portion of the metal layer into a plurality of columns having a predetermined width;

(u) irradiating a first column in a first pass with a pulsed radiation beam having a predetermined pulsed repetition rate by translating the substrate having the metal layer at a predetermined translation velocity past a position of impingement of the pulsed radiation beam so that the pulsed radiation beam scans the entire length of the first column along a first irradiation path, each pulse of the pulsed radiation beam having an intensity pattern that includes a plurality of shadow regions and a plurality of beamlets, the intensity pattern of each pulse of the pulsed radiation beam having a width at least equal to the predetermined width of the columns, wherein during each pulse of the pulsed radiation beam, each region of the at least a portion of the metal layer overlapped by a respective one of the beamlets is melted throughout its entire thickness, and each region of the at least a portion of the metal layer overlapped by a respective one of the shadow regions remains at least partially unmelted, each at least partially unmelted region adjoining respective adjacent melted regions, the predetermined translation velocity of the metal layer and the predetermined pulse repetition rate of the pulsed radiation beam being chosen so that a melted region in a previous portion of the at least a portion of the metal layer irradiated by a previous pulse of the pulsed radiation beam completely resolidifies before a next portion which partially overlaps the previous portion is irradiated by a next pulse of the pulsed radiation beam, the first pass being a previous pass and the first irradiation path being a previous irradiation path for further processing;

(v) shifting the substrate having the metal layer by a relatively small distance in a direction perpendicular to the columns to thereby shift the shadow regions and beamlets of the intensity pattern of each pulse of the pulsed radiation beam with respect to the at least a portion of the metal layer;

(w) irradiating the first column in a next pass with the pulsed radiation beam having the predetermined pulse repetition rate and the shifted radiation beam pulse intensity pattern by translating the substrate having the metal layer at the predetermined translation velocity past the position of impingement of the pulsed radiation beam so that the pulsed radiation beam scans the entire length of the first column in a next pass along a next irradiation path, wherein during each pulse of the pulsed radiation beam, each region of the at least a portion of the metal layer overlapped by a respective one of the shifted beamlets is melted throughout its entire thickness, and each region of the at least a portion of the metal layer overlapped by a respective one of the shifted shadow regions remains at least partially unmelted, each one of the at least partially unmelted regions adjoining respective adjacent melted regions, the predetermined translation velocity of the metal layer and the predetermined pulse repetition rate of the pulsed radiation beam being chosen so that a melted region in a previous portion of the at least a portion of the metal layer irradiated by a previous pulse of the pulsed radiation beam completely resolidifies before a next portion which partially overlaps the previous portion is irradiated by a next pulse of the pulsed radiation beam;

(x) repeating steps (c) and (d) in combination, if needed, with the next pass being a previous pass and the next irradiation path being a previous irradiation path for further processing until a desired grain structure is obtained in the first column;

(y) translating the substrate having the metal layer so that the metal layer is positioned with respect to the pulsed radiation beam for irradiation of a next column of the at least a portion of the metal layer in a first pass;

(z) repeating steps (b), (c) and (d), and (e), if needed, in combination with the first column being the next column for further processing until a desired grain structure is obtained in the next column; and

(aa) repeating steps (f) and (g) in combination with the next column being a further column for further processing until a desired grain structure is obtained in each column of the at least a portion of the metal layer.

48. The method of claim 47, wherein the intensity pattern of each pulse of the pulsed radiation beam has a plurality of regularly spaced-apart, relatively narrow, linear, stripe-like shadow regions and a plurality of regularly spaced-apart, relatively wide, linear, stripe-like beamlets, each one of the beamlets being positioned in between and adjoining respective adjacent shadow regions, the shadow regions and beamlets being parallel to the columns of the at least a portion of the metal layer, and the shifting of the metal layer is by a distance that causes each one of the beamlets to overlap a respective one of the at least partially unmelted regions in the first pass and to partially overlap columns of grains in respective adjoining regions melted and resolidified in the first pass.

49. The method of claim 47, wherein the pulsed radiation beam is a pulsed laser beam.

50. The method of claim 49, wherein the pulsed laser beam is a pulsed excimer laser beam.

51. The method of claim 47, wherein the pulsed radiation beam is a chopped continuous wave laser beam.

52. The method of claim 47, wherein the pulsed radiation beam is a pulsed electron beam.

53. The method of claim 47, wherein the pulsed radiation beam is a pulsed ion beam.