Backflow reactor liner for protection of growth surfaces and for balancing flow in the growth liner

Patent metadata

Field	Value
Publication number	US-9577143-B1
Application number	US-201313917408-A
Country	US
Kind code	B1
Filing date	Jun 13, 2013
Priority date	Jun 15, 2012
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A backflow liner in an epitaxial growth system is provided in order to control gas flow and protect the surface of substrates throughout an epitaxial growth cycle. The backflow liner provides critical protection during the warming time prior to substrate pre-treatment, while the growth environment reaches steady state condition between the pre-treatment and the growth process, during pauses between the layer depositions in case of multilayer structure growth, and during the cooling process. The direction of the gas flow through the backflow liner is counter to the deposition gas flows directed from the source end of the growth system. The backflow liner is therefore designed to shape the flow of gases to prevent formation of the vortex-type streams in the growth system that may negatively affect the growth process.

First claim

What is claimed is:

1. An epitaxial growth system comprising:
a growth reactor;
a growth liner having an entrance and an exit at each end of the growth liner;
a substrate holder;
a source zone;
a backflow liner having an entrance and an exit at each end of the backflow liner, the exit of the backflow liner comprising a predominately rectangular or oblong cross-section;
a backflow liner source; and
a reactor exhaust;
the backflow liner having an axis substantially aligned with an axis of the growth liner;
the entrance of the backflow liner being coupled to the backflow liner source and the exit of the backflow liner being oblique to the axis of the backflow liner, wherein the exit of the growth liner having a flow directing wall larger than the exit of the backflow liner;
the oblique exit of the backflow liner being disposed adjacent to the flow directing wall of the growth liner exit, such that the oblique exit of the backflow liner and the flow directing wall of the growth liner exit being separated by a gap to directly face each other, whereby two counter-flowing gas streams from each of the backflow liner and the growth liner are combined and directed toward the reactor exhaust through the gap;
the substrate holder being mounted within the growth reactor for movement between a position within the growth liner to a position within the backflow liner while holding at least one substrate.

2. The epitaxial growth system of claim 1 wherein the oblique angle is approximately 45 degrees.

3. The epitaxial growth system of claim 1 wherein the backflow liner comprises a sapphire, silicon dioxide, aluminum oxide, silicon carbide, boron nitride, or a combination thereof, backflow liner.

4. The epitaxial growth system of claim 1 wherein the backflow source is coupled to a source of NH 3 , N 2 , Ar, or a mixture thereof.

5. The epitaxial growth system of claim 4 wherein the backflow liner is configured to protect surfaces of epitaxial growth substrates during a heat-up time prior to a pretreatment, protects epitaxial growth substrates while a growth environment reaches steady-state condition between a pretreatment and a growth process, or prevents decomposition of epitaxial growth products after the growth process when the NH 3 , N 2 , Ar, or a mixture thereof is flowing through the backflow liner.

6. The epitaxial growth system of claim 4 wherein the reactor is a Hydride Vapor Phase Epitaxy crystal growth reactor.

7. The epitaxial growth system of claim 1 wherein the reactor comprises a horizontal-flow, hot-wall Hydride Vapor Phase Epitaxy reactor for the growth of III-nitride semiconductors.

8. The epitaxial growth system of claim 1 wherein the growth liner has a predominantly rectangular cross-section.

9. The epitaxial growth system of claim 1 wherein the reactor is for the growth of uniform layers and multilayer structures and devices on sapphire substrates having one of generally c-, m-, r-, or a-plane orientation.

10. The epitaxial growth system of claim 1 for the growth of one or more layers of Al x In y Ga 1-x-y where x and y range from 0 to 1, inclusive and x+y≦1.

11. The epitaxial growth system of claim 10 for growing the one or more layers of Al x In y Ga 1-x-y on a group III-nitride substrate.

12. The epitaxial growth system of claim 10 wherein the one or more layers of Al x In y Ga 1-x-y in conjunction with an initial substrate constitutes a group III-nitride template.

13. The epitaxial growth system of claim 10 wherein the one or more layers of Al x In y Ga 1-x-y in conjunction with a starting substrate constitutes a light emitting diode structure on the substrate.

14. The epitaxial growth system of claim 10 wherein the one or more layers of Al x In y Ga 1-x-y in conjunction with a starting substrate constitutes a laser diode structure on the substrate.

15. The epitaxial growth system of claim 10 wherein the one or more layers of Al x In y Ga 1-x-y in conjunction with a starting substrate, constitutes a transistor structure on the substrate.

16. An epitaxial growth system comprising:
a Hydride Vapor Phase Epitaxy crystal growth reactor for the growth of III-nitride semiconductors;
a growth liner having an entrance and an exit at each end of the growth liner;
a substrate holder;
a source zone;
a silicon dioxide, aluminum oxide, silicon carbide, or boron nitride backflow liner having an entrance and an exit at each end of the backflow liner, the exit of the backflow liner comprising a predominately rectangular or oblong cross-section;
a backflow liner source of NH3, N2 or their mixture with argon coupled to the backflow liner; and
a reactor exhaust;
the backflow liner having an axis substantially aligned with an axis of the growth liner;
the entrance of the backflow liner being coupled to the backflow liner source and the exit of the backflow liner being oblique to the axis of the backflow liner, wherein the exit of the growth liner having a flow directing wall larger than the exit of the backflow liner;
the oblique exit of the backflow liner being disposed adjacent to the flow directing wall of the growth liner exit, such that the oblique exit of the backflow liner and flow directing wall of the growth liner exit being separated by a gap to directly face each other, whereby two counter-flowing gas streams from each of the backflow liner and the growth liner are combined and directed toward the reactor exhaust through the gap;
the substrate holder being mounted within the growth reactor for movement between a position within the growth liner to a position within the backflow liner while holding at least one substrate.

17. The epitaxial growth system of claim 16 wherein the backflow liner is configured to protect surfaces of epitaxial growth substrates during the heat-up time prior to pretreatment, protects epitaxial growth substrates while a growth environment reaches a steady-state condition between the pretreatment and the growth process, or prevents decomposition of epitaxial growth products after the growth process when the NH 3 , N 2 , Ar or a mixture thereof is flowing through the backflow liner.

18. The epitaxial growth system of claim 16 wherein the reactor comprises a horizontal-flow, hot-wall Hydride Vapor Phase Epitaxy reactor.

19. The epitaxial growth system of claim 16 wherein the reactor comprises a vertical-flow, hot-wall Hydride Vapor Phase Epitaxy reactor.

20. The epitaxial growth system of claim 16 wherein the growth liner has a predominantly rectangular cross-section.

21. The epitaxial growth system of claim 16 wherein for the growth of uniform layers and multilayer structures and devices on sapphire substrates having one of generally c-, m-, r-, or a-plane orientation.

22. The epitaxial growth system of claim 16 for the growth of uniform layers and multilayer structures and devices on one or more substrates comprising silicon, silicon carbide, lithium aluminate, magnesium aluminate, or sapphire.

Assignees

• Ostendo Technologies Inc

Inventors

• Shapovalov Lisa
• Kovalenkov Oleg
• Ivantsov Vladimir
• Syrkin Alexander

Classifications

• C23C16/45504

  Laminar flow · CPC title

• C23C16/45519 Primary

  Inert gas curtains · CPC title

• C30B25/165

  the flow of the reactive gases · CPC title

• C30B23/02

  Epitaxial-layer growth · CPC title

• C30B25/16

  Controlling or regulating (controlling or regulating in general G05) · CPC title