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US 6,198,157 B1Granted
Semiconductor device having buried boron and carbon regions
AssigneeHitachi, Ltd.
InventorsHidetsugu Ishida, Seiichi Isomae
Life of this patent
Estimating the term…
Abstract
To improve the gettering performance by ion implanting boron and improves the production yield of the semiconductor device by using an epitaxial wafer of good quality suppressing the occurrence of dislocations. For this purpose, an epitaxial wafer in which an epitaxial layer of about 1 μm is formed to a CZ semiconductor substrate implanted with boron ions which are dopant and carbon ions which are not a dopant is provided, and transistors are formed on the surface of the epitaxial layer.
Claims11
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type;
- an epitaxial layer of the first conductivity type formed on the substrate, the epitaxial layer having a surface;
- a well region of a conductivity type formed in said epitaxial layer, said well region extending from the surface of the epitaxial layer to said substrate and having a surface;
- and
- a gate insulating layer formed on the surface of said well region,
- wherein the well region includes implanted boron impurities and implanted carbon impurities, and wherein both the implanted carbon impurities and the implanted boron impurities are in localized regions in the well region.
3 more elements
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type;
- an epitaxial layer of the first conductivity type formed on said substrate, said epitaxial layer having a surface;
- a well region of a conductivity type formed in said epitaxial layer, said well region extending from the surface of said epitaxial layer to said substrate and having a surface;
- and
- a gate insulating layer formed on the surface of said well region,
- wherein said well region comprises (1) implanted boron impurities having a first distribution with a peak concentration spaced from the surface of said well region, and (2) implanted carbon impurities having a second distribution with a peak concentration spaced from said surface of said well region, and wherein a depth of said peak concentration of said first distribution and a depth of said peak concentration of said second distribution are substantially equal.
3 more elements
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type;
- an epitaxial layer of said first conductivity type formed on said substrate;
- a well region including a localized boron region having an impurity concentration higher than that of said well region and a localized carbon region having an impurity concentration higher than that of said well region;
- source and drain regions, of a second conductivity type, disposed in said well region, said second conductivity type being opposite said first conductivity type;
- a gate oxide film overlying a surface portion of said well region between said source and drain regions;
- and
- a gate electrode overlying said gate oxide film.
4 more elements
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type;
- an epitaxial layer of said first conductivity type formed on said substrate, said epitaxial layer having a surface;
- a well region of a second conductivity type opposite to said first conductivity type, having its impurity concentration gradually lowered depthwise of said epitaxial layer and formed to extend from the surface of said epitaxial layer to said semiconductor substrate, said well region including a localized boron region having an impurity concentration higher than that of said well region and a localized carbon region having an impurity concentration higher than that of said well region;
- source and drain regions of a second conductivity type disposed in said well region, said second conductivity type being opposite said first conductivity type;
- a gate oxide film overlying a surface portion of said well region between said source and drain regions;
- and
- a gate electrode overlying said gate oxide film.
4 more elements
Dependencies are inferred from the claim text.