Vapor phase epitaxy method

Patent metadata

Field	Value
Publication number	US-11955334-B2
Application number	US-202017129744-A
Country	US
Kind code	B2
Filing date	Dec 21, 2020
Priority date	Dec 20, 2019
Publication date	Apr 9, 2024
Grant date	Apr 9, 2024

Abstract

A vapor phase epitaxy method of growing a III-V layer with a doping profile that changes from a p-doping to an n-doping on a surface of a substrate or a preceding layer from the vapor phase from an epitaxial gas flow, at least one first precursor for an element of main group III, and at least one second precursor for an element of main group V. When a first growth height is reached, a first initial doping level is set by means of a ratio of a first mass flow of the first precursor to a second mass flow of the second precursor in the epitaxial gas flow, and subsequently, by stepwise or continuously changing the ratio of the first mass flow to the second mass flow and by stepwise or continuously increasing a mass flow of a third precursor for an n-type dopant in the epitaxial gas flow.

First claim

What is claimed is:

1. A vapor phase epitaxy method comprising:
growing a III-V layer on a substrate in a reaction chamber from a vapor phase from an epitaxial gas flow comprising a carrier gas, at least one first precursor for Galium, and at least one second precursor for an Arsine compound;
during said growing, setting, when a first growth height of the Ill-V layer is reached, a first initial doping level via a ratio of a first mass flow of the first precursor to a second mass flow of the second precursor in the epitaxial gas flow;
during said growing, changing, stepwise or continuously, the ratio of the first mass flow of the first precursor to the second mass flow of the second precursor; and
during said growing, increasing, stepwise or continuously, a mass flow of a third Silane precursor for an n-type dopant in the epitaxial gas flow, doping of the III-V layer with a growth height of at least 10 μm being changed until a target n-doping level of at most 5·10 16 cm −3 is reached.

2. The vapor phase epitaxy method according to claim 1 , wherein the first initial doping level is an initial p-doping level and is at most 5·10 16 cm −3 .

3. The vapor phase epitaxy method according to claim 1 , wherein the first initial doping level is an initial n-doping level and is at most 1·10 15 cm −3 .

4. The vapor phase epitaxy method according to claim 1 , wherein the growth height of the junction region layer is at least 30 μm.

5. The vapor phase epitaxy method according to claim 1 , wherein the doping over the junction region layer is changed over every 5 μm of growth height by at most 1·10 13 cm −3 .

6. The vapor phase epitaxy method according to claim 1 , wherein the doping over the junction region layer is changed in at least four steps.

7. The vapor phase epitaxy method according to claim 1 , wherein the element of main group Ill is gallium and the element of main group V is arsenic.

8. The vapor phase epitaxy method according to claim 1 , wherein the third precursor is monosilane.

9. The vapor phase epitaxy method according to claim 1 , wherein the first initial doping level is set starting from a second initial p-doping level by an abrupt change in the ratio of the first mass flow to the second mass flow.

10. The vapor phase epitaxy method according to claim 9 , wherein the second initial p-doping level is at most 5·10 16 cm 3 .

11. The vapor phase epitaxy method according to claim 9 , wherein the second initial p-doping level is at most 1·10 16 cm −3 .

12. The vapor phase epitaxy method according to claim 1 , wherein the doping of the III-V layer, preceding the first growth height is reduced by continuously and/or stepwise changing the ratio of the first mass flow to the second mass flow from a starting p-doping level of at least 5·10 16 cm −3 to the first initial doping level or to a second initial p-doping level.

13. The vapor phase epitaxy method according to claim 1 , wherein after the target n-doping level has been reached, growth is continued further over a growth height of at least 10 μm with the settings for the target n-doping level.

14. The vapor phase epitaxy method according to claim 1 , wherein after the target n-doping level has been reached, a further target n-doping level is set by abruptly changing the third mass flow and/or by abruptly changing the ratio of the first mass flow to the second mass flow, wherein the second target n-doping level is greater than the target n-doping level.

15. The vapor phase epitaxy method according to claim 1 , wherein the first initial doping level is an initial p-doping level and is at most 1·10 16 cm −3 .

16. The vapor phase epitaxy method according to claim 1 , wherein the first initial doping level is an initial p-doping level and is at most 1·10 15 cm −3 .

17. The vapor phase epitaxy method according to claim 1 , wherein the first initial doping level is an initial p-doping level and is at most 5·10 14 cm −3 .

18. The vapor phase epitaxy method according to claim 1 , wherein the first initial doping level is an initial n-doping level and is at most 5·10 14 cm −3 .

19. The vapor phase epitaxy method according to claim 1 , wherein the first initial doping level is an initial n-doping level and is at most 1·10 14 cm −3 .

20. The vapor phase epitaxy method according to claim 1 , wherein the target n-doping level is at most 1·10 16 cm −3 .

21. The vapor phase epitaxy method according to claim 1 , wherein the target n-doping level is at most 1·10 16 cm −3 .

22. The vapor phase epitaxy method according to claim 1 , wherein the target n-doping level is at most 5·10 14 cm −3 .

23. The vapor phase epitaxy method according to claim 1 , wherein a growth height of the junction region layer is at least 60 μm.

24. The vapor phase epitaxy method according to claim 1 , wherein the doping of the Ill-V layer, preceding the first growth height is reduced by continuously and/or stepwise changing the ratio of the first mass flow to the second mass flow from a starting p-doping level of at least 1·10 17 cm −3 to the first initial doping level or to a second initial p-doping level.

Assignees

• Azur Space Solar Power Gmbh

Inventors

• Keller Gregor
• WAECHTER Clemens
• Wierzkowski Thorsten

Classifications

• H10P14/3442

  N-type · CPC title

• H10P14/3421

  Arsenides · CPC title

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title

• H10D62/10

  Shapes, relative sizes or dispositions of the regions of the semiconductor bodies; Shapes of the semiconductor bodies · CPC title

• H10P14/3444 Primary

  P-type · CPC title