Semiconductor device

• US 7,875,898 B2
• Filed: 09/21/2007
• Issued: 01/25/2011
• Est. Priority Date: 01/24/2005
• Status: Active Grant

• Current Assignee: Pannova Semic, LLC (Vector Capital Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Maeda, Syuusaku
• Primary Examiner(s): Roman; Angel
• Application Number:
  US11/859,092
• Publication Number:
  US 20080012037A1
• Time in Patent Office: 1,222 Days
• Field of Search: 438/33, 438/462, 257 98-100, 257/E33.005, 257/E33.006, 257/E33.066
• US Class Current: 257/99
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• 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 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination

Abstract

The inventive method for manufacturing a semiconductor device is a method for manufacturing a semiconductor device using irradiation with laser light to partition a substrate having semiconductor layers formed thereon, with gallium contained in at least one of the substrate and the semiconductor layers, wherein the method comprises: forming grooves to be used as boundaries between individual substrates by irradiating the substrate along partitioning locations with laser light, immersing the substrate into an acid solution, and partitioning the substrate into individual substrates along the boundaries where grooves are formed. In this manner, it provides a method for manufacturing a semiconductor device in which, during the partitioning of a gallium-containing semiconductor device substrate, deposits of gallium compounds adhered during laser irradiation are removed, partitioning surfaces are formed flat and uniform, and the incidence of electrode continuity failures and resin peeling is low.

Claims

1. A semiconductor device manufactured by using irradiation with laser light to partition a substrate having semiconductor layers formed thereon, with gallium nitride contained in at least one of the substrate and the semiconductor layers, wherein

grooves to be used as boundaries between individual substrates are formed by irradiating the substrate along partitioning locations with laser light,

the substrate is partitioned into the individual substrates along the boundaries where the grooves are formed, whereby a slope made by the irradiation with laser light is left,

the substrate is immersed into an acid solution before or after the foregoing partitioning so that deposits of gallium compounds that have sublimed due to the irradiation with laser light and adhered to the substrate or electrodes are removed,

the individual substrates is sealed with a resin,

the grooves extend to not less than 30% and not more than 60% of the thickness of the substrate, and are each formed into a quasi V-shape cross-section so that the slope made by the irradiation with laser light is an inclined slope that is inclined at 20°

to 60°

with respect to a normal to the substrate,

wherein the semiconductor device is a light-emitting element,

wherein the light-emitting element has an n-type semiconductor layer and a p-type semiconductor layer formed on top of the substrate, and

wherein a Pt layer and, on top of it, a rhodium layer, are formed in the p-type semiconductor layer region in order to establish an ohmic contact with the p-type semiconductor layer, thereby producing a dual layer structure acting as a reflective film, with a p-type electrode composed of gold formed thereon.

2. The semiconductor device according to claim 1, wherein locations irradiated with laser light have grooves formed by irradiation on the side opposite the side on which the semiconductor layers are formed.

3. The semiconductor device according to claim 1, wherein the grooves are formed by performing irradiation with laser light in an oblique direction so as to form the quasi V-shaped cross-sections.

4. The semiconductor device according to claim 1, wherein locations irradiated with laser light have grooves formed by irradiation on the side on which the semiconductor layers are formed.

5. The semiconductor device according to claim 1, wherein the acid solution is a solution whose main ingredient is hydrochloric acid or nitric acid.

6. The semiconductor device according to claim 1, wherein a Ti layer and, on top of the Ti layer, a Au layer, are formed in the n-type semiconductor layer region in order to establish an ohmic contact with the n-type semiconductor layer, thereby producing a dual layer structure acting as an n-type electrode.

7. The semiconductor device according to claim 1,

wherein an electrode of at least one selected from the substrate and the semiconductor layers is connected electrically with another electrode.

8. The semiconductor device according to claim 7, wherein locations irradiated with laser light have grooves formed by irradiation on the side opposite the side on which the semiconductor layers are formed.

9. The semiconductor device according to claim 7, wherein the grooves are formed by performing irradiation with laser light in an oblique direction so as to form quasi V-shaped cross-sections.

10. The semiconductor device according to claim 7, wherein locations irradiated with laser light have grooves formed by irradiation on the side on which the semiconductor layers are formed.

11. The semiconductor device according to claim 7, wherein the acid solution is a solution whose main ingredient is hydrochloric acid or nitric acid.

12. The semiconductor device according to claim 7, wherein the semiconductor device is a light-emitting element.

13. The semiconductor device according to claim 7, wherein the grooves extend to not less than 30% of the thickness of the substrate.

14. The semiconductor device according to claim 12, wherein the light-emitting element has an n-type semiconductor layer and a p-type semiconductor layer formed on top of the substrate.

15. The semiconductor device according to claim 14, wherein a Pt layer and, on top of it, a rhodium layer, are formed in the p-type semiconductor layer region in order to establish an ohmic contact with the p-type semiconductor layer, thereby producing a dual layer structure acting as a reflective film, with a p-type electrode composed of gold formed thereon.

16. The semiconductor device according to claim 14, wherein a Ti layer and, on top of it, a Au layer, are formed in the n-type semiconductor layer region in order to establish an ohmic contact with the n-type semiconductor layer, thereby producing a dual layer structure acting as an n-type electrode.