TOP > 外国特許検索 > Compound semiconductor, method for manufacturing same, and nitride semiconductor

Compound semiconductor, method for manufacturing same, and nitride semiconductor

外国特許コード F210010552
整理番号 AE06-01US1
掲載日 2021年8月2日
出願国 アメリカ合衆国
出願番号 202017086753
公報番号 20210047720
出願日 令和2年11月2日(2020.11.2)
公報発行日 令和3年2月18日(2021.2.18)
優先権データ
  • 特願2016-169994 (2016.8.31) JP
  • 201916329037 (2019.2.27) US
  • 2017JP20513 (2017.6.1) WO
発明の名称 (英語) Compound semiconductor, method for manufacturing same, and nitride semiconductor
発明の概要(英語) A compound semiconductor has a high electron concentration of 5×1019 cm-3 or higher, exhibits an electron mobility of 46 cm2/V·s or higher, and exhibits a low electric resistance, and thus is usable to produce a high performance semiconductor device. The present invention provides a group 13 nitride semiconductor of n-type conductivity that may be formed as a film on a substrate having a large area size at a temperature of room temperature to 700° C.
従来技術、競合技術の概要(英語) BACKGROUND ART
Devices using group 13 nitride semiconductors such as GaN and InN are now put into practical use in a wide range of products. Conventionally, an MOCVD method and an MBE method have been used for crystal growth of such a group 13 nitride semiconductor. However, the MOCVD method requires a process temperature exceeding 1000° C. The MBE method allows a compound semiconductor film to be formed at a low temperature, but is not suitable to mass manufacturing because there is a limit on the area size of the film that may be formed and the manufacturing cost is high.
With the MBE method, if donors are incorporated at a high concentration, absorption by the high concentration donor level generated in the forbidden band in the vicinity of the conduction band of the crystal structure occurs. For this reason, the MBE method has a problem that the transparency of the manufactured compound semiconductor film is decreased (Non-patent Document 1). For these reasons, the MOCVD method is now used to manufacture a compound semiconductor, mainly, to manufacture a nitride semiconductor fora practical use.
Currently, next-generation electronic devices having both a high withstand voltage and a low on-resistance are desired. In order to realize such an electronic device, it is desired to realize a two-, three-, or four-component compound semiconductor, more specifically, a compound semiconductor device using a group 13 nitride semiconductor. This requires further improvement in the quality of the crystal of such a compound semiconductor and improvement in the refinement of the doping technology. Especially for a vertical power device to be formed on a GaN substrate, it is urged to decrease the carbon concentration of an n-type drift layer and to improve the electron mobility. There are the following documents describing the prior art.
Patent Document 1 discloses a semiconductor device including a buffer layer formed of a metal nitride and a semiconductor layer, which are provided on a copper substrate.
Patent Document 2 discloses examples of a semiconductor substrate including a graphite plate having a thickness of 10 to 100 μm, containing a sintered polymer and having a heat resistance and flexibility, a buffer layer formed of HfN on the graphite plate, and a semiconductor layer formed of GaN on the buffer layer.
Patent Document 3 discloses a method for manufacturing a group-III-V compound semiconductor by epitaxial growth on a ZnO substrate.
Non-patent Document 1 discloses research results on formation of a p-type GaN semiconductor layer. Non-patent Document 2 discloses research results on the contact resistance of a p-type GaN semiconductor layer. Non-patent Document 3 discloses research results on a low concentration doping technology into a nitride semiconductor. Non-patent Document 4 discloses research results on a transport model of electrons in a high electric field. Non-patent Document 5 discloses research results on a model of carrier mobility of GaN. Non-patent Document 6 discloses research results on evaluation of the contact resistance against a p-type GaN formed by a PSD method. Non-patent Document 7 discloses examples of experiments of producing an LED on glass. Non-patent Document 8 discloses research results on a nitride single crystal grown by the PSD method.
特許請求の範囲(英語) [claim1]
1. A nitride semiconductor having n-type conductivity and containing nitrogen and at least one group 13 element selected from the group consisting of B, Al, Ga and In,
wherein the nitride semiconductor has an electron concentration of 1×1020 cm-3 or higher and exhibits a specific resistance of 0.3×10-3 Ω·cm or lower.

[claim2]
2. The nitride semiconductor according to claim 1, wherein the electron concentration is 2×1020 cm-3 or higher.

[claim3]
3. The nitride semiconductor according to claim 1, wherein the nitride semiconductor has a contact resistance of 1×10-4 Ω·cm2 or lower against an n-type ohmic electrode metal.

[claim4]
4. The nitride semiconductor according to claim 1, wherein the nitride semiconductor contains oxygen as an impurity at 1×1017 cm-3 or higher.

[claim5]
5. The nitride semiconductor according to claim 4, wherein the nitride semiconductor has an absorption coefficient of 2000 cm-1 or lower to light having a wavelength region of 405 nm.

[claim6]
6. The nitride semiconductor according to claim 4, wherein the nitride semiconductor has an absorption coefficient of 1000 cm-1 or lower to light having a wavelength region of 450 nm.

[claim7]
7. The nitride semiconductor according to claim 1, wherein the nitride semiconductor has an RMS value of 5.0 nm or less obtained by a surface roughness measurement performed by an AFM.

[claim8]
8. The nitride semiconductor according to claim 1, wherein the at least one group 13 element is Ga.

[claim9]
9. The nitride semiconductor according to claim 1, wherein the nitride semiconductor contains either one of, or both of, Si and Ge as donor impurities.

[claim10]
10. The nitride semiconductor according to claim 1, wherein the specific resistance is 0.2×10-3 Ω·cm or higher.

[claim11]
11. The nitride semiconductor according to claim 1, wherein the specific resistance is 0.15×10-3 Ω·cm or higher.

[claim12]
12. The nitride semiconductor according to claim 1, wherein the specific resistance is 0.1×10-3 Ω·cm or higher.

[claim13]
13. The nitride semiconductor according to claim 1, wherein the nitride semiconductor fulfills a numerical range enclosed by four points at which:
(a) the electron concentration is 1×1020 cm-3 and the specific resistance is 0.3×10-3 Ω·cm,
(b) the electron concentration is 3×1020 cm-3 and the specific resistance is 0.3×10-3 Ω·cm,
(c) the electron concentration is 4×1020 cm-3 and the specific resistance is 0.15×10-3 Ω·cm, and
(d) the electron concentration is 9×1020 cm-3 and the specific resistance is 0.15×10-3 Ω·cm.

[claim14]
14. A contact structure comprising the nitride semiconductor according to claim 1 for a conductive portion.

[claim15]
15. A contact structure comprising the nitride semiconductor according to claim 1 for an electrode.

[claim16]
16. A semiconductor device comprising the contact structure according to claim 14.

[claim17]
17. A semiconductor device comprising the contact structure according to claim 15.
  • 発明者/出願人(英語)
  • FUJIOKA HIROSHI
  • UENO KOHEI
  • JAPAN SCIENCE AND TECHNOLOGY AGENCY
国際特許分類(IPC)
ライセンスをご希望の方、特許の内容に興味を持たれた方は、問合せボタンを押してください。

PAGE TOP

close
close
close
close
close
close