Abstract A bipolar transistor (100) and a method for forming the same. A base-link diffusion source layer (118) is formed over a portion of the collector region (102). The base-link diffusion source layer (118) comprises a material that is capable of being used as a dopant source and is capable of being etched selectively with respect to silicon. A base electrode (114) is formed over at least one end portion of the base-link diffusion source layer (118) and the exposed portions of the base-link diffusion source layer (118) are removed. An extrinsic base region (110) is diffused from the base electrode (114) and a base link-up region (112) is diffused from the base-link diffusion source layer (118). Processing may then continue to form an intrinsic base region (108), emitter region (126), and emitter electrode (124).
A bipolar transistor comprising: a collector region; an intrinsic base region within said collector region; an extrinsic base region within said collector region; a base link-up region within said collector region between said intrinsic base region and said extrinsic base region; a base-link diffusion source layer above and substantially coextensive with said base link-up region; a base electrode above said extrinsic base layer, said base electrode and said base-link diffusion source layer made of different materials; and an emitter region within said intrinsic base region.
Claim 2
Dependent Claim
85 words
A bipolar transistor comprising: a collector region; an intrinsic base region within said collector region; an extrinsic base region within said collector region; a base link-up region within said collector region between said intrinsic base region and said extrinsic base region; a base-link diffusion source layer above and substantially coextensive with said base link-up region; a base electrode above said extrinsic base layer, said base electrode and said base-link diffusion source layer made of different materials; and an emitter region within said intrinsic base region.
Claim 3
Dependent Claim
16 words
The biopolar transistor of claim 1, wherein said base-link diffusion source layer comprises a silicate glass.
Claim 4
Dependent Claim
15 words
The biopolar transistor of claim 1, wherein said base-link diffusion source layer comprises borosilicate glass.
Claim 5
Dependent Claim
16 words
The bipolar transistor of claim 1, wherein said base-link diffusion source layer comprises a phosphosilicate glass.
Claim 6
Dependent Claim
14 words
The biopolar transistor of claim 1, wherein said base-link diffusion source layer comprises silicon-germanium.
Claim 7
Dependent Claim
38 words
The bipolar transistor of claim 1, wherein said bipolar transistor comprises two layers of polysilicon, a first of said layers of polysilicon forming said base electrode and a second of said layers of polysilicon abutting said emitter region.