Method for fabricating and separating semiconductor devices

• US 7,459,373 B2
• Filed: 11/15/2005
• Issued: 12/02/2008
• Est. Priority Date: 11/15/2004
• Status: Expired due to Fees

• Current Assignee: Verticle, Inc.
• Original Assignee: Verticle, Inc.
• Inventors: Yoo, Myung Cheol
• Primary Examiner(s): LEBENTRITT, MICHAEL
• Application Number:
  US11/280,142
• Publication Number:
  US 20060105542A1
• Time in Patent Office: 1,113 Days
• Field of Search: 438/455, 156/273.5, 257/E21.175, 257/E21.508, 257/E21.238
• US Class Current: 438/455
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture
• CPC Class Codes: H01L 21/3043 Making grooves, e.g. cutting
• CPC Class Codes: H01L 21/32134 by liquid etching only
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 2221/6835 used as a support during build up manufacturing of active devices
• CPC Class Codes: H01L 2221/68354 used to support diced chips prior to mounting
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

A method of fabricating and separating semiconductor structures comprises the steps of: (a) partially forming a semiconductor structure attached to a support structure, the partially formed semiconductor structure comprising a plurality of partially formed devices, where the partially formed devices are attached to one another by at least one connective layer; (b) forming a partial mask layer over at least a part of the partially formed devices; (c) etching the connective layer to separate the devices; and (d) removing the partial mask layer. Advantages of the invention include higher yield than conventional techniques. In addition, less expensive equipment can be used to separate the devices. The result is a greater production of devices per unit of time and per dollar.

Claims

1. A method of fabricating and separating semiconductor structures comprising the steps of:

(a) partially forming a semiconductor structure attached to a support structure, the partially formed semiconductor structure comprising a plurality of partially formed devices, where the partially formed devices are attached to one another by at least one connective layer;

(b) forming a partial mask layer over at least a part of the partially formed devices;

(c) etching the connective layer to separate the devices; and

(d) removing the partial mask layer,

wherein an Au layer can be etched away with gold etchant, such as potassium chloride.

2. The method of claim 1, further comprising the step of depositing an oxide passivation layer on at least a part of the partially formed devices between steps (a) and (b).

3. The method of claim 1, wherein step (a) includes the steps of forming a device mask layer over the devices, partially etching the semiconductor structure between the devices down to the at least one connective layer and removing the device mask.

4. The method of claim 1, further comprising the step of treating a GaN layer of the devices to create undulations thereon.

5. The method of claim 1, further comprising the step of separately mounting the devices on a polymer base support film which is inert to base etching chemicals and suitable for die expansion and consecutive packaging processes.

6. The method of claim 5, wherein the semiconductor devices are protected with a chemically inert oxide layer and a polymer layer prior to chemical etching.

7. The method of claim 6, wherein the oxide layer remains on the device Surface, while the polymer protective layer is stripped after device separation process.

8. The method of claim 5, wherein the etching chemicals is a solution comprising chlorine.

9. The method of claim 6, wherein etching method is either chemical jet spray or immersing in the etching solution.

10. A method of fabricating a semiconductor device, comprising the steps of:

(a) partially forming a semiconductor structure attached to a support structure, the partially formed semiconductor structure comprising, a plurality of partially formed devices;

(b) depositing a metal laser over the partially formed semiconductor structure;

(c) finishing forming the semicondudor structure;

(d) forming a mask layer over the surface of the metal layer, the mask layer formed in a plurality of rectangles leaving lanes where each of the devices are desired to be separated from each other;

(e) removing the metal layer where the lanes are positioned, the mask layer protecting the metal layer under the rectangles;

(f) separating the devices proximate to where the metal layer was removed; and

(f) removing the mask layer from the devices.

11. The method of claim 10, further comprising the step of fixing the metal layer to a wafer carrier between steps (b) and (c) and removing the metal layer from the wafer carrier between steps (c) and (d).

12. A method of fabricating and separating semiconductor structures comprising the steps of:

(a) partially forming a semiconductor structure attached to a support structure, the partially formed semiconductor structure a plurality of partially formed devices;

(b) forming a partial mask layer over the surface of the partially formed semiconductor structure, the partial mask layer formed in a grid pattern leaving openings where each of the devices are desired to be formed;

(c) depositing a metal layer over the partially formed semiconductor structure in the openings where the surface is not covered by the partial mask layer;

(d) finishing forming the semiconductor structure;

(e) removing the partial mask layer; and

(f) separating the devices proximate to where the partial mask layer was removed.

13. The method of claim 12, further comprising the step of fixing the metal layer to a wafer carrier between steps (c) and (d) and removing the metal layer from the wafer carrier between steps (d) and (e).

14. The method of claim 12, further comprising the step of depositing an oxide passivation layer on at least a part of the partially formed devices between steps (d) and (e).

15. The method of claim 12, wherein step (d) includes the steps of forming a device mask layer over the devices, partially etching the semiconductor structure between the devices down to the partial mask layer and removing the device mask.

17. The method of claim 12, further comprising the step of separately mounting the devices on a polymer base support him which is inert to base stripping chemicals and suitable for die expansion and consecutive packaging processes.

20. The method of claim 17, wherein etching method is either chemical jet spray or immersing in the etching solution.

21. The method of claim 17, wherein an Au layer can be etched away with cold etchant, such as potassium chloride.

16. The method of c aim 12, further comprising the step of treating a GaN layer of the devices to create undulations thereon.

18. The method of claim 16, wherein the semiconductor devices are protected with a chemically inert oxide layer prior to chemical etching.

19. The method of claim 16, wherein the stripping chemicals is a solution comprising chlorine base acidic chemicals, such as (OH)⁻

containing chemicals.