US4662983A
Expired / Lapsed
US
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Multiple meltback procedure for LPE growth on InP
Assignee: Nokia Bell Labs
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Filing: 1985-05-03
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Granted: 1987-05-05
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Expires: 2005-05-03
Abstract
Abstract A multiple meltback procedure is described for removing gross contaminants and thermal degradation from InP-containing surfaces. Prior to LPE growth on an InP substrate, the substrate surface is brought into contact briefly (≲1 sec) with an essentially pure In melt and is then brought into contact with a slightly undersaturated In/P melt. A similar triple meltback procedure is described for use prior to LPE growth over a mesa (e.g., in the fabrication of buried heterostructures).
Inventors
- 👤 Brymer H. Chin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:58
CPC Classifications
C; C30; C30B; C30B29/00; C30B29/10; C30B29/40; C30B19/00; C30B19/12; H; H10; H10P; H10P14/00; H10P14/20; H10P14/26; H10P14/263; H10P14/265; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2909; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3218; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3418; H10P14/36; H10P14/3602; Y; Y10; Y10S; Y10S148/00; Y10S148/017; Y10S148/131; Y10S438/00; Y10S438/955; Y10S438/974
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
97 words
In the manufacture of a device, which includes a layer on the surface of an InP-containing semiconductor body, a method of preparing the surface comprising the steps of: (a) heating the body to an elevated temeprature, (b) bringing the surface into contact with an essentially pure In melt for a time period long enough to remove gross contaminants, but short enough to avoid formation of surface ripples, and (c) bringing the surface into contact with a melt mixture of In slightly undersaturated with P for a time period long enough to remove thermal degradation from the surface.
Claim 2
Dependent Claim
97 words
In the manufacture of a device, which includes a layer on the surface of an InP-containing semiconductor body, a method of preparing the surface comprising the steps of: (a) heating the body to an elevated temeprature, (b) bringing the surface into contact with an essentially pure In melt for a time period long enough to remove gross contaminants, but short enough to avoid formation of surface ripples, and (c) bringing the surface into contact with a melt mixture of In slightly undersaturated with P for a time period long enough to remove thermal degradation from the surface.
Claim 3
Dependent Claim
25 words
The method of claim 1 including, after step (c), the additional step of growing the layer as at least one epitaxial layer on the surface.
Claim 4
Dependent Claim
28 words
The method of claim 2 including, after step (c), the steps of growing the layer as a plurality of epitiaxial layers on the surface to form a heterostructure.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein all of the steps are performed in an ambient of flowing gas selected from the group consisting of hydrogen nitrogen and helium.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein, in step (a), the body is heated to a temperature in the range of about 600 to 700 degrees C.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein, during step (b), the surface is maintained in contact with the melt for a time period ≲1 sec.
Claim 8
Dependent Claim
27 words
The method of claim 6 wherein, during step (c), the surface is maintained in contact with the melt mixture for a time period of about 5-120 sec.
Claim 9
Dependent Claim
44 words
The method of claim 1 including, between steps (b) and (c), the additional step (b') of bringing the surface into contact with a melt of material selected from the group consisting of essentially pure In and a mixture of In slightly undersaturated with P.
Claim 10
Dependent Claim
27 words
The method of claim 8 wherein the surface is moved in continuous fashion from contact with the melt in step (b) to the melt in step (b').
Claim 11
Dependent Claim
26 words
The method of claim 8 wherein, in step (c), the surface is maintained in contact with the melt for a time period of about 5 sec.
Claim 12
Independent Claim
18 words
The method of claims 8, 9, or 10 wherein the body has a raised feature on the surface.
Claim 13
Dependent Claim
44 words
The method of claim 11 including the steps of epitaxially growing a heterostructure of layers on the surface and etching the layers to form a mesa constituting the raised feature, and including the step of growing at least one epitaxial layer over the mesa.
Claim 14
Independent Claim
138 words
A method of manufacturing a device, which includes preparing the surface of an InP substrate for liquid phase epitaxial growth of a layer thereon, comprising the steps of: (a) heating the substrate to an elevated temperature suitable for epitaxial growth in gas, (b) bringing the surface into contact with an essentially pure In melt for a time period long enough to remove gross contaminants from the surface, but short enough to avoid formation of surface ripples, (c) bringing the surface into contact with a melt mixture of In slightly undersatured with P at the temperature of step (a), thereby to remove thermal degradation from the surface caused by the evaporation of P therefrom, and (d) bringing the surface into contact with a source melt for a time period effective to grow the layer thereon to the desired thickness.
Claim 15
Independent Claim
138 words
A method of manufacturing a device, which includes preparing the surface of an InP substrate for liquid phase epitaxial growth of a layer thereon, comprising the steps of: (a) heating the substrate to an elevated temperature suitable for epitaxial growth in gas, (b) bringing the surface into contact with an essentially pure In melt for a time period long enough to remove gross contaminants from the surface, but short enough to avoid formation of surface ripples, (c) bringing the surface into contact with a melt mixture of In slightly undersatured with P at the temperature of step (a), thereby to remove thermal degradation from the surface caused by the evaporation of P therefrom, and (d) bringing the surface into contact with a source melt for a time period effective to grow the layer thereon to the desired thickness.
Claim 16
Dependent Claim
17 words
The method of claim 13 wherein, in step (d), an In-containing layer is grown on the surface.
Claim 17
Dependent Claim
54 words
The method of claim 14 wherein in step (a) the substrate is heated to a temperature of about 600-700 degrees C. in a gas selected from the group consisting of hydrogen, nitrogen and helium, and in step (b) the surface is maintained in contact with the pure In melt for a time ≲1 sec.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |