Method for fabricating GaInP/GaAs structures
AssigneeTexas Instruments Incorporated
InventorsWilliam U. Liu, Shou-Kong Fan, Timothy S. Henderson, Darrell G. Hill
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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.
Claims24
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 .mu.m may be fabricated.
The method of claim 4 wherein said etch solution also contains an acdd.
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.
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.sub.3 +SF.sub.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.
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.
Dependencies are inferred from the claim text.