ENHANCING THE WIDTH OF POLYCRYSTALLINE GRAINS WITH MASK

• US 20100099273A1
• Filed: 12/22/2009
• Published: 04/22/2010
• Est. Priority Date: 09/16/2003
• Status: Active Grant

• 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.
• Granted Patent: US 8,063,338 B2
• Time in Patent Office: Days
• US Class Current: 438/795
• CPC Class Codes: B23K 26/066 by using masks
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0268 Shape of mask
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: H01L 21/02691 Scanning of a beam
• CPC Class Codes: H01L 21/268 using electromagnetic radiation, e.g. laser radiation
• CPC Class Codes: H01L 27/1285 using control of the annealing or irradiation parameters, e.g. using different scanning direction or intensity for different transistors
• CPC Class Codes: H01L 27/1296 adapted to increase the uniformity of device parameters
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: Y10S 117/904 Laser beam

Abstract

A system, method and masking arrangement are provided of enhancing the width of polycrystalline grains produced using sequential lateral solidification using a modified mask pattern is disclosed. One exemplary mask pattern employs rows of diamond or circular shaped areas in order to control the width of the grain perpendicular to the direction of primary crystallization.

Claims

1. A masking arrangement for processing a thin film sample comprising:

a first section which includes at least one opaque area arranged in a first pattern, the first section is configured to receive at least one beam pulse thereon, and produce at least one first modified pulse when the at least one beam pulse is passed therethrough, the at least one first modified pulse including at least one first portion having a pattern that corresponds to the first pattern of the first section, wherein, when the first portion is irradiated on the sample, at least one first region of the sample is prevented from being completely melted throughout its thickness; and

a second section associated with the first section, the second section including a further area arranged in a second pattern, the second section being configured to receive at least one further beam pulse thereon, and produce at least one second modified pulse when the at least one further beam pulse is passed therethrough, the at least one second modified pulse including at least one second portion having a pattern that corresponds to the second pattern of the second section, wherein, when the second portion is irradiated on the sample, at least one second region of the sample irradiated by the second portion is completely melted throughout its thickness,

wherein when the first region is irradiated by the at least one second modified pulse, the second portion of the at least one second modified pulse completely melts the at least one first region throughout its thickness.

2. The masking arrangement as in claim 1, wherein at least one of the first pattern and the second pattern comprises at least one of diamond areas, oval areas, dot areas and round areas.

3. The masking arrangement as in claim 1, wherein,

the first pattern extends approximately along a first horizontal axis, the first pattern having a width measured along the vertical axis,

a second area of the second section extends approximately along the first horizontal axis, the second section being configured to permit the at least one first region to be completely melted throughout its thickness by the second modified pulse, the second area being offset horizontally from the first pattern, the second area having a width measured in the vertical axis that is at least equal to the width of the first pattern, and

the second pattern extends approximately along a second horizontal axis and vertically offset from the first horizontal axis, wherein the second pattern is configured to prevent at least one third region of the sample from being completely melted throughout its thickness.

4. A masking arrangement as in claim 3, wherein the first section includes

at least one further opaque area arranged in a third pattern extending approximately along a third horizontal axis,

wherein the third horizontal axis is vertically offset from the first horizontal axis,

wherein the third pattern is substantially aligned vertically with the first pattern,

wherein the third pattern is configured to prevent at least one fourth region of the sample from being completely melted throughout its thickness,

wherein a position of the third horizontal axis is such that the second horizontal axis is between the first horizontal axis and the third horizontal axis.

5. The masking arrangement as in claim 4, wherein the third pattern comprises at least one of diamond areas, oval areas, dot areas and round areas.

6. The masking arrangement of claim 3, wherein the second horizontal axis extends approximately along a centerline in between the first and third horizontal axes.

7. The masking arrangement of claim 4, wherein,

elements of the first pattern are approximately equidistant from other elements of the first pattern, and

elements of the third pattern are approximately equidistant from other elements of the third pattern.

8. The mask arrangement of claim 1, wherein the second pattern comprises one or more substantially parallel lines.

9. A method for processing a thin film sample, comprising the steps of:

providing at least one beam on a first section of a masking arrangement to produce at least one first modified pulse when the at least one beam is passed therethrough, the first section which includes at least one opaque area arranged in a first pattern, the at least one first modified pulse including at least one first portion having a pattern that corresponds to the first pattern, wherein, when the first portion is irradiated on the sample, at least one first region of the sample is prevented from being completely melted throughout its thickness;

based on the dimensions of the masking arrangement, translating at least one of the thin film sample and the beam relative to the other one of the thin film sample and the beam; and

providing at least one further beam on a second section of a masking arrangement to produce at least one second modified pulse when the at least one further beam is passed therethrough, the second section associated with the first section, the second section including a further area arranged in a second pattern, the at least one second modified pulse including at least one second portion having a pattern that corresponds to the second pattern, wherein, when the second portion is irradiated on the sample, at least one second region of the sample irradiated by the second portion is completely melted throughout its thickness;

wherein, when the first region is irradiated by the at least one second modified pulse, the second portion of the at least one second modified pulse completely melts the at least one first region throughout its thickness.

10. The method of claim 9, wherein at least one of the first pattern and the second pattern comprises at least one of diamond areas, oval areas, dot areas and round areas.

11. The method of claim 9, wherein,

the first pattern extends approximately along a first horizontal axis, the first pattern having a width measured along the vertical axis,

a second area of the second section extends approximately along the first horizontal axis, the second section being configured to permit the at least one first region to be completely melted throughout its thickness by the at least one second modified pulse, the second area being offset horizontally from the first pattern, the second area having a width measured in the vertical axis that is at least equal to the width of the first pattern, and

the second pattern extends approximately along a second horizontal axis and vertically offset from the first horizontal axis, wherein the second pattern is configured to prevent at least one third region of the sample from being completely melted throughout its thickness.

12. The method of claim 11, wherein the first section includes

at least one further opaque area in a third pattern extending approximately along a third horizontal axis,

wherein the third horizontal axis is vertically offset from the first horizontal axis,

wherein the third pattern is substantially aligned vertically with the first pattern,

wherein the third pattern is configured to prevent at least one fourth region of the sample from being completely melted throughout its thickness,

wherein a position of the third horizontal axis is such that the second horizontal axis is between the first horizontal axis and the third horizontal axis.

13. The method of claim 12, wherein the third pattern comprises at least one of diamond areas, oval areas, dot areas and round areas.

14. The method of claim 11, wherein the second horizontal axis is approximately along a centerline in between the first and third horizontal axes.

15. The method of claim 12, wherein,

elements of the first pattern are approximately equidistant from other elements of the first pattern, and

elements of the third pattern are approximately equidistant from other elements of the third pattern.

16. The method of claim 9, wherein the second pattern comprises one or more substantially parallel lines.

17. A system for processing a thin film sample, comprising:

a mask,

a processor to activate a device to irradiate through the mask, the processor being configured to perform the steps of;

providing at least one beam on a first section of a masking arrangement to produce at least one first modified pulse when the at least one beam is passed therethrough, the first section which includes at least one opaque area arranged in a first pattern, the at least one first modified pulse including at least one first portion having a pattern that corresponds to the first pattern, wherein, when the first portion is irradiated on the sample, at least one first region of the sample is prevented from being completely melted throughout its thickness,

based on the dimensions of the masking arrangement, translating at least one of the thin film sample and the beam relative to the other one of the thin film sample and the beam, and

providing at least one further beam on a second section of a masking arrangement to produce at least one second modified pulse when the at least one further beam is passed therethrough, the second section associated with the first section, the second section including a further area arranged in a second pattern, the at least one second modified pulse including at least one second portion having a pattern that corresponds to the second pattern, wherein, when the second portion is irradiated on the sample, at least one second region of the sample irradiated by the second portion is completely melted throughout its thickness;

wherein, when the first region is irradiated by the at least one second modified pulse, the second portion of the at least one second modified pulse completely melts the at least one first region throughout its thickness.

18. The system of claim 17, wherein at least one of the first pattern and the second pattern comprises at least one of diamond areas, oval areas, dot areas and round areas.

19. The system of claim 17, wherein,

the first pattern extends approximately along a first horizontal axis, the first pattern having a width measured along the vertical axis,

a second area of the second section extends approximately along the first horizontal axis, the second section being configured to permit the at least one first region to be completely melted throughout its thickness by the at least one second modified pulse, the second area being offset horizontally from the first pattern, the second area having a width measured in the vertical axis that is at least equal to the width of the first pattern, and

the second pattern extends approximately along a second horizontal axis and vertically offset from the first horizontal axis, wherein the second pattern is configured to prevent at least one third region of the sample from being completely melted throughout its thickness.

20. The system of claim 19, wherein the first section includes

at least one further opaque area extending in a third pattern approximately along a third horizontal axis,

wherein the third horizontal axis is vertically offset from the first horizontal axis,

wherein the third pattern is substantially aligned vertically with the first pattern,

wherein the third pattern is configured to prevent at least one fourth region of the sample from being completely melted throughout its thickness,

wherein a position of the third horizontal axis is such that the second horizontal axis is between the first horizontal axis and the third horizontal axis.

21. The system of claim 20, wherein the third pattern comprises at least one of diamond areas, oval areas, dot areas and round areas.

22. The system of claim 20, wherein the second horizontal axis is approximately along a centerline in between the first and third horizontal axes.

23. The system of claim 22, wherein,

elements of the first pattern are approximately equidistant from other elements of the first pattern, and

elements of the third pattern are approximately equidistant from other elements of the third pattern.

24. The system of claim 19, wherein the second pattern comprises one or more substantially parallel lines.