US5411632A
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US
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Method for the etching of a heterostructure of materials of the III-V group
Assignee: Thales SA
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Filing: 1993-11-05
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Granted: 1995-05-02
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Expires: 2013-11-05
Abstract
Abstract Disclosed is a method for the etching of at least two layers of semiconductor materials having different natures, with a view to making a mesa for the self-alignment of the metallizations of a transistor. The heterojunction must comprise a first layer of a material containing As, which is etched by reactive ion etching, and a second layer of a material containing P which is etched chemically. Application to the making of HBT type vertical heterojunction transistors.
Inventors
- 👤 Sylvain Delage
- 👤 Herve Blanck
- 👤 Simone Cassette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:33
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/021; H10D10/80; H10D10/821; H10D62/00; H10D62/80; H10D62/82; H10D62/824; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/246; H10P50/60; H10P50/64; H10P50/642; H10P50/646; H10P50/69; H10P50/691; H10P50/692; Y; Y10; Y10S; Y10S438/00; Y10S438/978
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
134 words
A method for the etching of a heterostructure of layers of group III-V semiconductor materials, for the making of a heterojunction transistor, said method being one wherein the heterojunction comprises at least one first layer of a compound containing arsenic (such as GaAs, AlGaAs etc.) which is etched by a first reactive ion etching, and a second layer of a compound containing phosphorus (such as InP, GaInP etc.) which is etched by an aqueous solution of hydrochloric acid (HCl); wherein the chemical corrosion, by HCl, of the second layer is preceded by a cleansing of the surface by means of a second reactive ion etching localized on a thickness of the order of 100 angstroms, this cleansing being made necessary by the presence of interdiffusions at the interface of the first and second layers.
Claim 2
Independent Claim
134 words
A method for the etching of a heterostructure of layers of group III-V semiconductor materials, for the making of a heterojunction transistor, said method being one wherein the heterojunction comprises at least one first layer of a compound containing arsenic (such as GaAs, AlGaAs etc.) which is etched by a first reactive ion etching, and a second layer of a compound containing phosphorus (such as InP, GaInP etc.) which is etched by an aqueous solution of hydrochloric acid (HCl); wherein the chemical corrosion, by HCl, of the second layer is preceded by a cleansing of the surface by means of a second reactive ion etching localized on a thickness of the order of 100 angstroms, this cleansing being made necessary by the presence of interdiffusions at the interface of the first and second layers.
Claim 3
Dependent Claim
25 words
A method of etching according to claim 1, wherein the first layer is etched by a plasma of CCl 2 F 2 or SiCl .
Claim 4
Dependent Claim
27 words
A method of etching according to claim 1, wherein the second layer is partially etched with a plasma of CH 4 +H 2 or by ion bombardment.
Claim 5
Independent Claim
123 words
A method of forming a heterostructure of layers of group III-V semiconductor material comprising the steps of: creating a structure having a first layer which serves as a mask, a second layer, under the first layer, including a compound containing arsenic, and a third layer, under the second layer, including a compound containing phosphorous; etching the second layer using a reactive ion etching such that the first layer serves as a protective layer and the reactive ion etching reduces: a cross-section area of the second layer as a distance from the first layer increases; etching the third layer by an aqueous solution of hydrochloric acid such that as a distance from the second layer increases, a cross-sectional area of the third layer decreases.
Claim 6
Independent Claim
123 words
A method of forming a heterostructure of layers of group III-V semiconductor material comprising the steps of: creating a structure having a first layer which serves as a mask, a second layer, under the first layer, including a compound containing arsenic, and a third layer, under the second layer, including a compound containing phosphorous; etching the second layer using a reactive ion etching such that the first layer serves as a protective layer and the reactive ion etching reduces: a cross-section area of the second layer as a distance from the first layer increases; etching the third layer by an aqueous solution of hydrochloric acid such that as a distance from the second layer increases, a cross-sectional area of the third layer decreases.
Claim 7
Dependent Claim
38 words
A method according to claim 4, wherein after etching of the second layer and before the etching of the third layer, there is a step of: a second reactive ion etching to cleanse interdiffusions at the third layer.
Claim 8
Dependent Claim
23 words
A method according to claim 4, wherein the second layer is etched by plasma of CCl 2 F 2 or SiCl 4 .
Claim 9
Dependent Claim
25 words
A method according to claim 5, wherein the third layer is partially etched with a plasma of CH 4 +H 2 or by ion bombardment.
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