Material-saving process for fabricating mixed crystals

• US 5,348,911 A
• Filed: 04/26/1993
• Issued: 09/20/1994
• Est. Priority Date: 06/30/1987
• Status: Expired due to Term

• Current Assignee: Aixtron GmbH
• Original Assignee: Aixtron GmbH
• Inventors: Deschler, Marc, Gruter, Klaus, Balk, Pieter, Jurgensen, Holger
• Primary Examiner(s): Breneman, R. Bruce
• Assistant Examiner(s): OJAN, OURMAZD
• Application Number:
  US08/051,792
• Time in Patent Office: 512 Days
• Field of Search: 437/102, 437/104, 437/81, 437/965, 437/128, 437/133, 437/126, 148/DIG.64, 148/DIG. 65, 148/DIG. 56, 427/248.1, 427/252, 427/255.2, 156/610, 156/613
• US Class Current: 117/91
• CPC Class Codes: B01D 7/02 Crystallisation directly from the vapour phase into single crystals C30B23/00
• CPC Class Codes: C23C 16/45557 Pulsed pressure or control pressure
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 29/40 AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
• CPC Class Codes: C30B 29/42 Gallium arsenide

Abstract

Disclosed is a process for fabricating mixed crystals and, in particular, III-V semiconductors, in which at least one component of the composition of the mixed crystal is transferred in a reactor from a source into a vapor phase containing hydrogen and chloride compounds as well as a carrier gas and mixed with said component or other components of said composition of said mixed crystal, transported to a substrate and precipitated on said substrate. The invented process is distinguished in that in order to vary the growth rate between approximately 1 <m/h and approximately 500 <m/h, the overall pressure is varied between approximately 80 mbar and approximately 1 mbar.

Claims

1. A process for fabricating mixed crystals comprising:

transferring at least one component of a composition of the mixed crystal in a reactor from a source into a vapor phase containing hydrogen and chloride compounds, said chloride compounds comprising at least HCl, a carrier gas, and said component;

transporting the vapor phase to a substrate;

precipitating the vapor phase on said substrate; and

varying a growth rate between 1 μ

m/h and 500 μ

m/h, wherein the step of varying the growth rate includes the steps of varying the overall pressure of the vapor phase between 80 mbar and 1 mbar, and varying the HCl partial pressure in the vapor phase between 5*10^-6 bar and 5*10^-3 bar.

2. A process according to claim 1, wherein the V main group element or elements are added as hydrogen compounds.

3. A process according to claim 2, wherein the partial pressure of said V main group elements present as hydrogen compounds is varied between 10^-4 bar and 10^-2 bar.

4. A process according to claim 1, wherein said component vaporized from a source is a III main group element.

5. A process according to claim 4, wherein said element is gallium.

6. A process according to claim 1, wherein the temperature of said source is 700°

C.

7. A process according to claim 1, wherein said carrier gas is N₂.

8. A process according to claim 1, wherein the V main group element or elements are added as hydrogen compounds.

9. A process according to claim 8, wherein the partial pressure of said V main group elements present as hydrogen compounds is varied between 10^-4 bar and 10^-2 bar.

10. A process according to claim 9, wherein said component vaporized from a source is a III main group element.

11. A process according to claim 10, wherein said element is gallium.

12. A process according to claim 11, wherein the temperature of said source is 700°

C.

13. A process according to claim 12, wherein said carrier gas is N₂.