US5330932A
Expired / Lapsed
US
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Method for fabricating GaInP/GaAs structures
Assignee: Texas Instruments Inc
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Filing: 1992-12-31
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Granted: 1994-07-19
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Expires: 2012-12-31
Abstract
Abstract In one form of the invention, a method is disclosed for removing portions of successive layers of GaAs 34 and GaInP 32 comprising the steps of: performing an anisotropic reactive ion etch on the GaAs layer; and performing an isotropic wet etch on the GaInP layer, whereby a mesa formed as a result of the reactive ion etch and the wet etch has substantially vertical sidewalls, and further whereby GaInP/GaAs structures having dimensions of less than approximately 3.0 mu m may be fabricated.
Inventors
- 👤 William U. Liu
- 👤 Shou-Kong Fan
- 👤 Timothy S. Henderson
- 👤 Darrell G. Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:24
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/021; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/246; H10P50/60; H10P50/64; H10P50/642; H10P50/646; H10D62/00; H10D62/80; H10D62/85; Y; Y10; Y10S; Y10S148/00; Y10S148/011
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
70 words
A method for removing portions of successive layers of GaAs and GaInP comprising the steps of: performing a reactive ion etch on said GaAs layer; and performing a wet etch on said GaInP layer, whereby a mesa formed as a result of said reactive ion etch and said wet etch has substantially vertical sidewalls, and further whereby GaInP/GaAs structures having dimensions of less than approximately 3.0 μm may be fabricated.
Claim 2
Independent Claim
70 words
A method for removing portions of successive layers of GaAs and GaInP comprising the steps of: performing a reactive ion etch on said GaAs layer; and performing a wet etch on said GaInP layer, whereby a mesa formed as a result of said reactive ion etch and said wet etch has substantially vertical sidewalls, and further whereby GaInP/GaAs structures having dimensions of less than approximately 3.0 μm may be fabricated.
Claim 3
Dependent Claim
44 words
The method of claim 1 further comprising the steps of: interposing a layer of AlGaAs between said layer of GaAs and said layer of GaInP wherein said reactive ion etch stops of said AlGaAS layer; and removing said AlGaAs layer with a wet etch.
Claim 4
Dependent Claim
50 words
The method of claim 1 further comprising the steps of: stopping said reactive ion etch before said GaInP layer is exposed, wherein a thin layer of GaAs is left above said GaInP layer; and etching said thin layer of GaAs with an etch solution containing H 2 O 2 .
Claim 5
Dependent Claim
13 words
The method of claim 4 wherein said etch solution also contains an acdd.
Claim 6
Dependent Claim
14 words
The method of claim 4 wherein said acid is H 2 SO 4 .
Claim 7
Dependent Claim
13 words
The method of claim 3 wherein said etch solution also contains a base.
Claim 8
Dependent Claim
15 words
The method of claim 1 wherein wet etch is performed with HCl as an etchant.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein said wet etch is performed with HCl:H 3 PO 4 (3:1 by volume).
Claim 10
Dependent Claim
25 words
The method of claim 1 wherein said GaInP is Ga x In 1-x P, wherein x is in the range of approximately 0.48 to 0.53.
Claim 11
Independent Claim
81 words
A method for removing portions of successive layers of GaAs and GaInP comprising the steps of: performing a reactive ion etch on said GaAs layer; stopping said reactive ion etch at a surface of said GaInP layer, wherein said reaction of a reactant in a plasma used in said reactive ion etching with said GaInP layer forms a residual layer that inhibits etching of said GaInP layer; ion milling said residual layer; and performing a wet etch on said GaInP layer.
Claim 12
Independent Claim
81 words
A method for removing portions of successive layers of GaAs and GaInP comprising the steps of: performing a reactive ion etch on said GaAs layer; stopping said reactive ion etch at a surface of said GaInP layer, wherein said reaction of a reactant in a plasma used in said reactive ion etching with said GaInP layer forms a residual layer that inhibits etching of said GaInP layer; ion milling said residual layer; and performing a wet etch on said GaInP layer.
Claim 13
Dependent Claim
18 words
The method of claim 10 wherein CLl 3 +SF 6 is a reactant in said reactive ion etch.
Claim 14
Dependent Claim
23 words
The method of claim 10 further comprising the step of performing a cleanup etch on said GaInP layer with a solution containing HF.
Claim 15
Independent Claim
154 words
A method for forming a heterojunction bipolar transistor comprising the steps of: patterning metallization over a material structure to form an emitter contact, said material structure comprising: a GaAs emitter cap layer; a GaInP emitter layer; a base layer; a collector layer; and a subcollector layer; performing a reaction ion etch on said emitter cap layer to remove portions of said material structure not covered by said patterned metallization, wherein CCl 3 +SF 6 is a reactant in said reactive ion etch; performing a wet etch to remove said GaInP layer from said material structure not covered by said patterned metallization to form an emitter mesa and to expose said base layer; forming base contacts on said base layer; removing said base layer from an aera surrounding said emitter mesa to form a base mesa; removing portions of said collector layer to expose said subcollector layer; and forming collector contacts on said subcollector layer.
Claim 16
Independent Claim
154 words
A method for forming a heterojunction bipolar transistor comprising the steps of: patterning metallization over a material structure to form an emitter contact, said material structure comprising: a GaAs emitter cap layer; a GaInP emitter layer; a base layer; a collector layer; and a subcollector layer; performing a reaction ion etch on said emitter cap layer to remove portions of said material structure not covered by said patterned metallization, wherein CCl 3 +SF 6 is a reactant in said reactive ion etch; performing a wet etch to remove said GaInP layer from said material structure not covered by said patterned metallization to form an emitter mesa and to expose said base layer; forming base contacts on said base layer; removing said base layer from an aera surrounding said emitter mesa to form a base mesa; removing portions of said collector layer to expose said subcollector layer; and forming collector contacts on said subcollector layer.
Claim 17
Dependent Claim
44 words
The method of claim 13 further comprising the steps of: interposing a layer of AlGaAs between said layer of GaAs and said layer of GaInP wherein said reactive ion etch stops on said AlGaAs layer; and removing said AlGaAs layer with a wet etch.
Claim 18
Dependent Claim
49 words
The method of claim 13 further comprising the steps off stopping said reactive ion etch before said GaInP layer is exposed, wherein a thin layer of GaAs is left above said GaInP layer; and etching said thin layer of GaAs with a solution containing H 2 O 2 .
Claim 19
Dependent Claim
13 words
The method of claim 15 wherein said etch solution also contains an acid.
Claim 20
Dependent Claim
14 words
The method of claim 16 wherein said acid is H 2 SO 4 .
Claim 21
Dependent Claim
13 words
The method of claim 15 wherein said etch solution also contains a base.
Claim 22
Dependent Claim
16 words
The method of claim 12 wherein said wet etch is performed with HCl as an etchant.
Claim 23
Dependent Claim
19 words
The method of claim 13 wherein said wet etch is performed with HCl:H 3 PO 4 (3:1 by volume).
Claim 24
Dependent Claim
26 words
The method of claim 12 wherein said GaInP is Ga x In 1-x , P, wherein x is in the range of approximately 0.48 to 0.53.
Claim 25
Independent Claim
192 words
A method for forming a heterojunction bipolar transistor comprising the steps of: patterning metallization over a material structure to form an emitter contact, said material structure comprising: a GaAs emitter cap layer; a GaInP emitter layer; a base layer; a collector layer; and a subcollector layer; performing a reaction ion etch on said emitter cap layer to remove portions of said material structure not covered by said patterned metallization; stopping said reactive ion etch at a surface of said GaInP layer, wherein said reaction of a rectant in a plasma used in said reactive ion etching growth said GaInP layer forms a residual layer that inhibits etching of said GaInP layer; ion milling said residual layer; and performing a wet etch to remove said GaInP layer from said portions of said material structure not covered by said patterned metallization to form an emitter mesa and to expose said base layer; forming base contacts on said base layer; removing said base layer from an area surrounding said emitter mesa to form a base mesa; removing portions of said collector layer to expose said subcollector layer; and forming collector contacts on said subcollector layer.
Claim 26
Independent Claim
192 words
A method for forming a heterojunction bipolar transistor comprising the steps of: patterning metallization over a material structure to form an emitter contact, said material structure comprising: a GaAs emitter cap layer; a GaInP emitter layer; a base layer; a collector layer; and a subcollector layer; performing a reaction ion etch on said emitter cap layer to remove portions of said material structure not covered by said patterned metallization; stopping said reactive ion etch at a surface of said GaInP layer, wherein said reaction of a rectant in a plasma used in said reactive ion etching growth said GaInP layer forms a residual layer that inhibits etching of said GaInP layer; ion milling said residual layer; and performing a wet etch to remove said GaInP layer from said portions of said material structure not covered by said patterned metallization to form an emitter mesa and to expose said base layer; forming base contacts on said base layer; removing said base layer from an area surrounding said emitter mesa to form a base mesa; removing portions of said collector layer to expose said subcollector layer; and forming collector contacts on said subcollector layer.
Claim 27
Dependent Claim
18 words
The method of claim 22 wherein BCl 3 +SF 6 is a reactant in said reactive ion etch.
Claim 28
Dependent Claim
23 words
The method of claim 22 further comprising the step of performing a cleanup etch on said GaInP layer with a solution containing HF.
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