EP0196897A1
Expired / Lapsed
EP
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Thermal etching of a compound semiconductor
Assignee: Fujitsu Ltd
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Filing: 1986-03-27
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Granted: —
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Expires: 2006-03-27
Abstract
Abstract A process for thermally etching a CaAs substrate prior to molecular beam epitaxy comprises the steps of: heating the GaAs substrate to above 750°C.- at which temperature both Ga and As are evaporated from the GaAs substrate- whilst irradiating it with an As molecular beam, thereby removing contamination adhering to the surface of the GaAs substrate. As the substrate evaporates it carries with it the contamination. The process can be performed by an apparatus comprising a prechamber (2), in which the surface is evaporated, connected to a growth chamber (6), in which an epitaxial layer is grown.
Inventors
- 👤 Junji Saito
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 16:52
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/90; H10P95/904; C; C30; C30B; C30B23/00; C30B23/02; C30B29/00; C30B29/10; C30B29/40; C30B29/42; H10P14/00; H10P14/20; H10P14/22; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2909; H10P14/2911; H10P14/2912; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3221; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; H10P14/3438; H10P14/3441; H10P14/3442; H10P14/36; H10P50/00; H10P50/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
79 words
A process for thermal-etching treatment of a compound semiconductor substrate for use in molecular beam epitaxy, comprising heating the compound semiconductor substrate to a temperature higher than that at which all elements of the compound semiconductor evaporate from the surface of the compound semiconductor substrate, whilst irradiating the compound semiconductor with an As molecular beam, thereby removing carbon or carbon compound contamination adhering to the surface of the compound semiconductor substrate by evaporating away part of the compound semiconductor.
Claim 2
Dependent Claim
79 words
A process for thermal-etching treatment of a compound semiconductor substrate for use in molecular beam epitaxy, comprising heating the compound semiconductor substrate to a temperature higher than that at which all elements of the compound semiconductor evaporate from the surface of the compound semiconductor substrate, whilst irradiating the compound semiconductor with an As molecular beam, thereby removing carbon or carbon compound contamination adhering to the surface of the compound semiconductor substrate by evaporating away part of the compound semiconductor.
Claim 3
Dependent Claim
66 words
A process for thermal-etching treatment of a GaAs substrate for use in a molecular beam epitaxy, comprising heating the GaAs substrate to a temperature higher than 750°C, at which temperature both Ga and As evaporate from the GaAs substrate, whilst irradiating a surface of the GaAs substrate with an As molecular beam thereby removing contamination adhering to the GaAs substrate by evaporating a part of it.
Claim 4
Dependent Claim
66 words
A process for thermal-etching treatment of a GaAs substrate for use in a molecular beam epitaxy, comprising heating the GaAs substrate to a temperature higher than 750°C, at which temperature both Ga and As evaporate from the GaAs substrate, whilst irradiating a surface of the GaAs substrate with an As molecular beam thereby removing contamination adhering to the GaAs substrate by evaporating a part of it.
Claim 5
Dependent Claim
26 words
A process according to claim 1 or 2, wherein the As molecular beam is irradiated at an As beam intensity of 1.5 x 10 5 Torr.
Claim 6
Dependent Claim
19 words
A process according to any one of the preceding claims, wherein the contamination includes carbon dioxide or carbon hydride.
Claim 7
Dependent Claim
26 words
A process according to any one of the preceding claims, wherein after removal of the contamination a thin GaAs buffer layer is formed on the substrate.
Claim 8
Dependent Claim
84 words
A process for thermal-etching treatment of a compound semiconductor substrate for use in molecular beam epitaxy, comprising heating the compound semiconductor substrate to a temperature higher than that at which all elements of the compound semiconductor evaporate from the surface of the compound semiconductor substrate with a molecular beam of the most volatile of the constituents of the compound semiconductor, thereby removing carbon or carbon compound contamination adhering to the surface of the compound semiconductor substrate by evaporating away part of the compound semiconductor.
Claim 9
Dependent Claim
84 words
A process for thermal-etching treatment of a compound semiconductor substrate for use in molecular beam epitaxy, comprising heating the compound semiconductor substrate to a temperature higher than that at which all elements of the compound semiconductor evaporate from the surface of the compound semiconductor substrate with a molecular beam of the most volatile of the constituents of the compound semiconductor, thereby removing carbon or carbon compound contamination adhering to the surface of the compound semiconductor substrate by evaporating away part of the compound semiconductor.
Claim 10
Independent Claim
133 words
An apparatus for performing a method in accordance with any one of the preceding claims, which comprises: a prechamber (2), for preparing a compound semiconductor substrate (101, provided with a heating holder (11) for holding and heating the compound semiconductor substrate (101 to a temperature higher than 750°C, at which temperature both Ga and As can be evaporated from the compound semiconductor, and provided with a molecular beam source (5) which irradiates the compound semiconductor substrate with a molecular beam of As; and, a growth chamber (6) in which a semiconductor crystalline layer is epitaxially grown, on to the substrate (101, the growth chamber (6) being a continuation of the prechamber (2) so that the substrate (10) is movable from the prechamber (2) into the growth chamber (6) without being exposed to contamination.
References Cited (Backward Citations)
US4493142A
Cited
EP0113983A1
Cited
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