Semiconductor device and method for manufacturing semiconductor device

• US 9,196,784 B2
• Filed: 08/14/2014
• Issued: 11/24/2015
• Est. Priority Date: 09/03/2013
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tajima, Jumpei, Katsuno, Hiroshi, Nunoue, Shinya, Ito, Toshihide
• Primary Examiner(s): Geyer, Scott B
• Application Number:
  US14/459,602
• Publication Number:
  US 20150060763A1
• Time in Patent Office: 467 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01L 21/28575 on semiconductor bodies comprising AIIIBV compounds
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/452 on AIII-BV compounds
• CPC Class Codes: H01L 29/66462 with a heterojunction interface channel or gate, e.g. HFET, HIGFET, SISFET, HJFET, HEMT
• CPC Class Codes: H01L 29/7787 with wide bandgap charge-carrier supplying layer, e.g. direct single heterostructure MODFET
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/40 Materials therefor

Abstract

According to one embodiment, a semiconductor device includes an n-type semiconductor layer and a first metal layer. The n-type semiconductor layer includes a nitride semiconductor. The n-type semiconductor layer includes a boron-containing region including boron bonded to oxygen. The first metal layer contacts the boron-containing region.

Claims

1. A semiconductor device, comprising:

an n-type semiconductor layer including a nitride semiconductor, the n-type semiconductor layer including a boron-containing region including boron bonded to oxygen; and

a first metal layer contacting the boron-containing region.

2. The device according to claim 1, wherein a boron concentration of the boron-containing region is 0.4 atomic % or more.

3. The device according to claim 1, wherein a silicon concentration of the boron-containing region is 5 atomic % or less.

4. The device according to claim 1, wherein

the n-type semiconductor layer is GaN including silicon, and

a ratio of a number of Si atoms to a number of Ga atoms in the boron-containing region is not more than 20%.

5. The device according to claim 1, wherein a thickness of the boron-containing region along a stacking direction from the first metal layer toward the n-type semiconductor layer is not less than 0.1 nanometers and not more than 10 nanometers.

6. The device according to claim 1, further comprising:

a p-type semiconductor layer including a nitride semiconductor; and

a light emitting layer provided between the n-type semiconductor layer and the p-type semiconductor layer.

7. The device according to claim 1, further comprising a gate electrode,

the boron-containing region including a first region and a second region, the second region being separated from the first region,

the first metal layer including a source electrode portion and a drain electrode portion, the source electrode portion contacting the first region, the drain electrode portion contacting the second region,

the gate electrode being disposed between the source electrode portion and the drain electrode portion.

8. The device according to claim 1, wherein the first metal layer includes Al.

9. The device according to claim 1, wherein the first metal layer includes at least one selected from Ti, Zn, and Ag.

10. A method for manufacturing a semiconductor device, comprising:

forming a boron-containing region in an n-type semiconductor layer including a nitride semiconductor by performing plasma processing of the n-type semiconductor layer in an atmosphere including BCl₃ gas, the boron-containing region including boron bonded to oxygen; and

forming a first metal layer on the boron-containing region to contact the boron-containing region.

11. The method according to claim 10, wherein the atmosphere further includes Ar gas.

12. The method according to claim 11, wherein a ratio of a flow rate of the BCl₃ gas to a flow rate of the Ar gas is 0.2 or more.

13. The method according to claim 10, wherein a processing time of the plasma processing is 1 minute or less.

14. The method according to claim 10, further comprising cleaning the n-type semiconductor layer with a cleansing agent including oxygen after the plasma processing and prior to the forming of the first metal layer.

15. The method according to claim 14, wherein the cleansing agent includes water.

16. The method according to claim 14, wherein time of the cleaning is 5 minutes or more.

17. The method according to claim 10, further comprising performing, after the forming of the first metal layer, heat treatment of the n-type semiconductor layer and the first metal layer in an inert gas atmosphere and/or at reduced pressure.

18. The method according to claim 17, wherein a temperature of the heat treatment is not less than 300°

C. and not more than 900°

C.

19. The method according to claim 17, wherein the inert gas atmosphere includes at least one selected from nitrogen and argon.

20. The method according to claim 17, wherein a time of the heat treatment is 30 seconds or more.