Low emitter resistance contacts to GaAs high speed HBT
AssigneeMicroLink Devices, Inc.
InventorsNoren Pan, Byung-Kwon Han
Life of this patent
Estimating the term…
Abstract
A heterojunction bipolar transistor is provided having an improved current gain cutoff frequency. The heterojunction bipolar transistor includes a contact region formed from InGaAsSb. The contact region allows an emitter region of the heterojunction bipolar transistor to realize a lower contact resistance value to yield an improved cutoff frequency (fT).
Claims45
A heterojunction bipolar transistor, comprising
- a substrate;
- a collector portion having at least one layer of a first material;
- a base portion having at least one layer of a second material;
- an emitter portion having at least one layer of said first material;
- and
- a contact portion having at least one layer of said first material and at least one layer of an InxGa1-x(As1-ySby) (0<x<0.7) (0<y<0.5).
A heterojunction bipolar transistor, comprising
- a substrate;
- a collector portion having at least one layer of a first material;
- a base portion having at least one layer of a second material;
- an emitter portion having at least one layer of a third material;
- and
- a contact having at least one layer of said first material and at least one layer of a InxGa1-x(As1-ySby) (0<x<0.7) (0<y<0.5) material.
A method for forming a compound semiconductor device, the method comprising the steps of:
- forming a collector stack having at least one layer of a first material on a substrate;
- forming a base stack having at least one layer of a second material on a portion of the collector stack;
- forming an emitter stack having at least one layer of said first material on a portion of the base stack;
- and
- forming a contact stack on a portion of the emitter stack, the contact stack having at least one layer of said first material and at least one layer of an InxGa1-x(As1-ySby) (0<x<0.7) (0<y<0.5) material.
A method for forming a compound semiconductor device, the method comprising the steps of:
- forming a collector stack having at least one layer of a first material on a substrate;
- forming a base stack having at least one layer of a second material on a portion of the collector stack;
- forming an emitter stack having at least one layer of a third material on a portion of the base stack;
- and
- forming a contact stack on a portion of the emitter stack, the contact stack having at least one layer of said first material and at least one layer of an InxGa1-x(As1-ySby) (0<x<0.7) (0<y<0.5) material.
Dependencies are inferred from the claim text.