Gallium nitride-based III-V group compound semiconductor device and method of producing the same

• US 5,563,422 A
• Filed: 04/28/1994
• Issued: 10/08/1996
• Est. Priority Date: 04/28/1993
• Status: Expired due to Term

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Chemical Industries Limited
• Inventors: Nakamura, Shuji, Yamada, Motokazu, Yamada, Takao, Senoh, Masayuki, Bando, Kanji
• Primary Examiner(s): WOJCIECHOWICZ, EDWARD JOSEPH
• Application Number:
  US08/234,001
• Time in Patent Office: 894 Days
• Field of Search: 257/13, 257/19, 257/22, 257/76, 257/103, 257/615, 257/741, 257/745, 257/750, 257/751, 257/763, 257/764, 257/765, 257/766, 257/770, 257/771
• US Class Current: 257/13
• CPC Class Codes: H01L 21/28575 on semiconductor bodies comprising AIIIBV compounds
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05082 Two-layer arrangements
• CPC Class Codes: H01L 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05166 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/05582 Two-layer coating
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05671 Chromium [Cr] as principal constituent
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/49109 outside the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01004 : Beryllium [Be]
• CPC Class Codes: H01L 2924/01012 : Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/12032 : Schottky diode
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2933/0016 : relating to electrodes
• CPC Class Codes: H01L 31/1884 : Manufacture of transparent electrodes, e.g. TCO, ITO
• CPC Class Codes: H01L 33/32 : containing nitrogen
• CPC Class Codes: H01L 33/325 : characterised by the doping materials
• CPC Class Codes: H01L 33/38 : with a particular shape
• CPC Class Codes: H01L 33/40 : Materials therefor
• CPC Class Codes: H01L 33/42 : Transparent materials
• CPC Class Codes: H01L 33/44 : characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: Y02E 10/50 : Photovoltaic [PV] energy

Abstract

A gallium nitride-based III-V Group compound semiconductor device has a gallium nitride-based III-V Group compound semiconductor layer provided over a substrate, and an ohmic electrode provided in contact with the semiconductor layer. The ohmic electrode is formed of a metallic material, and has been annealed.

Claims

1. A gallium nitride-based III-V Group compound semiconductor device, comprising:

a substrate having first and second major surface;

a semiconductor stacked structure arranged over said first major surface of the substrate, and comprising an n-type gallium nitride-based III-V Group compound semiconductor layer and a p-type gallium nitride-based III-V Group compound semiconductor layer;

a first electrode provided in electrical contact with said n-type semiconductor layer; and

a light-transmitting, second electrode provided in contact with said p-type semiconductor layer, and comprising a layer of nickel or a layer comprising nickel and gold, said second electrode establishing an ohmic contact with said p-type semiconductor layer.

2. The device according to claim 1, wherein a light emitted from the device is observed at a side of said first major surface of the substrate.

3. The device according to claim 1, wherein said second electrode comprises a layer of nickel provided in direct contact with said p-type semiconductor layer, and a layer of gold provided on said nickel layer.

4. The device according to claim 1, wherein said second electrode has a thickness of 0.001 μ

m to 1 μ

m.

5. The device according to claim 1, wherein said second electrode has been subjected to an annealing treatment at a temperature of 400°

C. or more.

6. The device according to claim 1, further comprising a lead frame supporting said device at said second major surface of the substrate.

7. The device according to claim 1, further comprising a bonding pad electrically connected to said second electrode, for bonding with a bonding wire.

8. The device according to claim 7, wherein said bonding pad is formed of gold or a metallic material comprising gold, and not containing aluminum or chromium.

9. The device according to claim 7, wherein said bonding pad is formed of a metallic material comprising gold and at least one metal selected from the group consisting of titanium, nickel, indium and platinum.

10. The device according to claim 7, wherein said bonding pad is formed of the same metallic material forming said second electrode.

11. The device according to claim 7, wherein said bonding pad comprises a layer of nickel provided in direct contact with said second electrode, and a layer of gold provided on said nickel layer.

12. The device according to claim 7, wherein said second electrode has a cut-off portion exposing a part of the surface of said p-type semiconductor layer, and said bonding pad is filled in said cut-off portion.

13. The device according to claim 12, wherein said bonding pad is formed of a metallic material which adheres to said p-type semiconductor layer more strongly than said second electrode.

14. The device according to claim 13, wherein said bonding pad is formed of aluminum, or a metallic material comprising at least two metals selected from the group consisting of chromium, aluminum and gold.

15. The device according to claim 7, wherein said bonding pad is arranged farthest from said first electrode.

16. The device according to claim 1, comprising a protective film formed of a transparent and electrically insulative material, and covering said second electrode.

17. The device according to claim 16, wherein said protective film is formed of silicon oxide, aluminum oxide, titanium oxide, or silicon nitride.

18. The device according to claim 16, wherein said protective film also covers a surface of said first electrode.

19. The device according to claim 7, further comprising a protective film formed of a transparent and electrically insulative material, and covering said second electrode and said bonding pad.

20. The device according to claim 19, wherein said protective film is formed of silicon oxide, aluminum oxide, titanium oxide, or silicon nitride.

21. The device according to claim 19, wherein said protective film also covers said first electrode.

22. A gallium nitride-based III-V Group compound semiconductor device, comprising:

a substrate having first and second major surfaces;

a semiconductor stacked structure arranged over said first major surface of the substrate, and comprising an n-type gallium nitride-based III-V Group compound semiconductor layer and a p-type gallium nitride-based III-V Group compound semiconductor layer;

a first electrode provided n contact with said n-type semi-conductor layer and comprising a first film comprising a combination of titanium with aluminum, and a second film provided on said first film and comprising a high-melting point metallic material having a melting point higher than aluminum, said first electrode establishing an ohmic contact with said n-type semiconductor layer; and

a second electrode provided in electrical contact with said p-type semiconductor layer.

23. The device according to claim 22, wherein said first electrode comprises a layer of titanium provided in direct contact with said n-type semiconductor layer, and a layer of aluminum, provided on said titanium layer.

24. The device according to claim 22, wherein said first electrode comprises a layer of titanium provided in direct contact with said n-type semiconductor layer, a layer of aluminum provided on said titanium layer, and a layer of gold provided on said aluminum layer.

25. The device according to claim 22, wherein said second film comprises titanium.

26. The device according to claim 22, wherein said second film comprises gold, and titanium and/or nickel.

27. The device according to claim 22, wherein said first electrode has been subjected to an annealing treatment at a temperature of 400°

C. or more.

28. The device according to claim 22, further comprising a lead frame supporting the device at said second major surface of the substrate.

29. The device according to claim 22, further comprising a bonding pad electrically connected to said second electrode, for bonding with a bonding wire

30. The device according to claim 29, wherein said bonding pad is arranged farthest from said first electrode.

31. The device according to claim 22, wherein said second electrode comprises nickel and gold.

32. A gallium nitride-based compound III-V group semiconductor device, comprising:

a substrate having first and second major surfaces;

a semiconductor stacked structure arranged over said first major surface of the substrate, and comprising an n-type gallium nitride-based III-V Group compound semiconductor layer and a p-type gallium nitride-based III-V Group compound semiconductor layer;

a first ohmic electrode provided in contact with said n-type semiconductor layer, and comprising a combination of titanium with aluminum; and

a light-transmitting, second ohmic electrode provided to cover substantially the entire surface of said p-type semiconductor layer.

33. The device according to claim 32, wherein said first ohmic electrode comprises a layer of titanium provided in direct contact with said n-type semiconductor layer, a layer of aluminum provided on said titanium layer, and a layer of gold provided on said aluminum layer.

34. The device according to claim 32, wherein said second ohmic electrode comprises a layer of nickel provided in direct contact with said p-type semiconductor layer and a layer of gold provided on said nickel layer.

35. The device according to claim 34, further comprising a bonding pad electrically connected to said second electrode, for bonding with a bonding wire.

36. The device according to claim 35, wherein said first major surface is substantially square, said bonding pad is arranged at a first corner portion of said second electrode, and said first electrode is arranged on said n-type semiconductor layer at a second corner portion thereof on a diagonal line of the square, including said first corner portion.

37. The device according to claim 36, wherein said bonding pad comprises a layer of nickel provided in direct contact with said second electrode, and a layer of gold provided on said nickel layer.

38. The device according to claim 36, wherein said second electrode has a cut-off portion exposing a portion of the surface of said p-type semiconductor layer, said bonding pad is filled in said cut-off portion, said bonding pad comprising a first layer comprising chromium or aluminum provided in direct contact with said p-type semiconductor layer, and a second layer comprising gold provided on said first layer.

39. The device according to claim 38, further comprising a transparent and electrically insulative protective film.

40. The device according to claim 39, further comprising a lead frame supporting the device at said second major surface of the substrate.

41. The device according to claim 40, wherein a light emitted from the device is observed at a side of said first major surface of the substrate.

42. A gallium nitride-based compound III-V Group semiconductor device, comprising:

a substrate having first and second major surfaces;

a semiconductor stacked structure arranged over said first major surface of the substrate, and comprising an n-type gallium nitride-based III-V Group compound semiconductor layer and a p-type gallium nitride-based III-V Group compound semiconductor layer;

a first electrode provided in electrical contact with said n-type semiconductor layer; and

a second electrode provided in contact with said p-type semiconductor layer and comprising a layer of nickel or a layer comprising nickel and gold, said layer of nickel or said layer comprising nickel and gold being provided in direct contact with said p-type semiconductor layer, said second electrode establishing an ohmic contact with said p-type semiconductor layer.

43. A gallium nitride-based compound III-V Group semiconductor device, comprising:

a substrate having first and second major surfaces;

a semiconductor stacked structure arranged over said first major surface of the substrate, and comprising an n-type gallium nitride-based III-V Group compound semiconductor layer and a p-type gallium nitride-based III-V Group compound semiconductor layer; and

an electrode assembly comprising a metallic material annealed to have an ohmic contact with the compound semiconductor layer, said electrode assembly including;

a first electrode provided in contact with said n-type semiconductor layer and comprising titanium and aluminum, or titanium and gold; and

a second electrode provided in contact with said p-type semiconductor layer and comprising nickel and gold.

44. A gallium nitride-based III-V Group compound semiconductor device, comprising an n-type gallium nitride-based III-V Group compound semiconductor layer, and an ohmic electrode provided in direct contact with said n-type semiconductor layer, said electrode comprising titanium and aluminum.

45. The device according to claim 44, wherein said electrode comprises a layer of titanium, and a layer of aluminum provided on said titanium layer.

46. A gallium nitride-based III-V Group compound semiconductor device, comprising an n-type gallium nitride-based III-V Group compound semiconductor layer, and an ohmic electrode provided in direct contact with an etched surface of said n-type semiconductor layer, said electrode comprising titanium and gold, and annealed at 400°

C. or more.

47. A gallium nitride-based III-V Group compound semiconductor device, comprising an n-type gallium nitride-based III-V Group compound semiconductor layer, and an ohmic electrode provided in direct contact with said n-type semiconductor layer, said electrode comprising titanium, aluminum and gold.

48. A gallium nitride-based III-V Group compound semiconductor device, comprising a p-type gallium nitride-based III-V Group compound semiconductor layer, and an ohmic electrode provided in direct contact with said p-type semiconductor layer, said electrode comprising nickel and gold.

49. The device according to claim 48, wherein said electrode comprises a layer of nickel, and a layer of gold provided on said nickel layer.