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US 8,575,648 B2Granted
Silicon carbide semiconductor device and method of manufacturing the same
AssigneeDenso Corporation
InventorsYuuichi Takeuchi, Rajesh Kumar Malhan, Naohiro Sugiyama
Life of this patent
Estimating the term…
Abstract
A silicon carbide semiconductor device having a JFET or a MOSFET includes a semiconductor substrate and a trench. The semiconductor substrate has a silicon carbide substrate, a drift layer on the silicon carbide substrate, a first gate region on the drift layer, and a source region on the first gate region. The trench has a strip shape with a longitudinal direction and reaches the drift layer by penetrating the source region and the first gate region. The trench is filled with a channel layer and a second gate region on the channel layer. The source region is not located at an end portion of the trench in the longitudinal direction.
Claims14
A silicon carbide semiconductor device having a JFET comprising:
- a semiconductor substrate including a first conductivity type silicon carbide substrate, a first conductivity type drift layer formed on the first conductivity type silicon carbide substrate by epitaxial growth, a second conductivity type first gate region formed on the drift layer by epitaxial growth, and a first conductivity type source region formed on the first gate region by epitaxial growth or ion implantation;
- a strip-shaped trench having a longitudinal direction and reaching the drift layer by penetrating the source region and the first gate region;
- a first conductivity type channel layer formed on an inner wall of the trench by epitaxial growth;
- and
- a second conductivity type second gate region formed on the channel layer, wherein
- the source region is not formed at an end portion of the trench in the longitudinal direction.
3 more elements
A silicon carbide semiconductor device having a MOSFET comprising:
- a semiconductor substrate including a first conductivity type silicon carbide substrate, a first conductivity type drift layer formed on the first conductivity type silicon carbide substrate by epitaxial growth, a second conductivity type base layer formed on the drift layer by epitaxial growth, and a first conductivity type source region formed on the base layer by epitaxial growth or ion implantation;
- a strip-shaped trench having a longitudinal direction and reaching the drift layer by penetrating the source region and the base layer;
- a first conductivity type channel layer formed on an inner wall of the trench by epitaxial growth;
- a gate insulation layer formed on the channel layer;
- and
- a gate electrode formed on a surface of the gate insulation layer in the trench, wherein
- the source region is not formed at an end portion of the trench in the longitudinal direction.
4 more elements
A silicon carbide semiconductor device having a JFET comprising:
- a semiconductor substrate including a first conductivity type silicon carbide substrate, a first conductivity type drift layer formed on the first conductivity type silicon carbide substrate by epitaxial growth, a second conductivity type first gate region formed on the drift layer by epitaxial growth, and a first conductivity type source region formed on the first gate region by ion implantation;
- a strip-shaped trench having a longitudinal direction and reaching the drift layer by penetrating the source region and the first gate region;
- a first conductivity type channel layer formed on an inner wall of the trench by epitaxial growth;
- and
- a second conductivity type second gate region formed on the channel layer, wherein
- the source region is formed at a long side portion of the trench and is not formed at an end portion of the trench in the longitudinal direction.
3 more elements
A silicon carbide semiconductor device having a MOSFET comprising:
- a semiconductor substrate including a first conductivity type silicon carbide substrate, a first conductivity type drift layer formed on the first conductivity type silicon carbide substrate by epitaxial growth, a second conductivity type base layer formed on the drift layer by epitaxial growth, and a first conductivity type source region formed on the base layer by epitaxial growth or ion implantation;
- a strip-shaped trench having a longitudinal direction and reaching the drift layer by penetrating the source region and the base layer;
- a first conductivity type channel layer formed on an inner wall of the trench by epitaxial growth;
- a gate insulation layer formed on the channel layer;
- and
- a gate electrode formed on a surface of the gate insulation layer in the trench, wherein
- the source region is formed at a long side portion of the trench and is not formed at an end portion of the trench in the longitudinal direction.
4 more elements
A method of manufacturing a silicon carbide semiconductor device having a JFET comprising:
- preparing a semiconductor substrate including a first conductivity type silicon carbide substrate, a first conductivity type drift layer formed on the first conductivity type silicon carbide substrate by epitaxial growth, a second conductivity type first gate region formed on the drift layer by epitaxial growth, and a first conductivity type source region formed on the first gate region by epitaxial growth or ion implantation;
- forming a strip-shaped trench having a longitudinal direction and reaching the drift layer by penetrating the source region and the first gate region;
- forming a first conductivity type channel layer on an inner wall of the trench by epitaxial growth;
- forming a second conductivity type second gate region on the channel layer;
- planarizing the channel layer and the second gate region until the source region is exposed;
- and
- removing the source region, the channel layer, and the second gate region at least at an end portion of the trench in the longitudinal direction by performing selective etching after the planarizing so that the end portion of the trench has a recess shape with a depth greater than a thickness of the source region.
4 more elements
A method of manufacturing a silicon carbide semiconductor device having a MOSFET comprising:
- preparing a semiconductor substrate including a first conductivity type silicon carbide substrate, a first conductivity type drift layer formed on the first conductivity type silicon carbide substrate by epitaxial growth, a second conductivity type base layer formed on the drift layer by epitaxial growth, and a first conductivity type source region formed on the base layer by epitaxial growth or ion implantation;
- forming a strip-shaped trench having a longitudinal direction and reaching the drift layer by penetrating the source region and the base layer;
- forming a first conductivity type channel layer on an inner wall of the trench by epitaxial growth;
- forming a gate insulation layer on the channel layer;
- and
- forming a gate electrode on a surface of the gate insulation layer in the trench;
- planarizing the gate electrode, the gate insulation layer, and the channel layer until the source region is exposed;
- and
- removing the source region, the channel layer, and the second gate region at least at an end portion of the trench in the longitudinal direction by performing selective etching after the planarizing so that the end portion of the trench has a recess shape with a depth greater than a thickness of the source region.
6 more elements
A method of manufacturing a silicon carbide semiconductor device having a JFET comprising:
- preparing a semiconductor substrate including a first conductivity type silicon carbide substrate, a first conductivity type drift layer formed on the first conductivity type silicon carbide substrate by epitaxial growth, a second conductivity type first gate region formed on the drift layer by epitaxial growth, and a first conductivity type source region formed on the first gate region by epitaxial growth or ion implantation;
- forming a strip-shaped trench having a longitudinal direction and reaching the drift layer by penetrating the source region and the first gate region;
- forming a first conductivity type channel layer on an inner wall of the trench by epitaxial growth;
- and
- forming a second conductivity type second gate region on the channel layer, wherein
- the preparing the semiconductor substrate includes forming the source region on the first gate region by ion implantation in such a manner that the source region is formed at a long side portion of the trench and is not formed at an end portion of the trench in the longitudinal direction.
3 more elements
A method of manufacturing a silicon carbide semiconductor device having a MOSFET comprising:
- preparing a semiconductor substrate including a first conductivity type silicon carbide substrate, a first conductivity type drift layer formed on the first conductivity type silicon carbide substrate by epitaxial growth, a second conductivity type base layer formed on the drift layer by epitaxial growth, and a first conductivity type source region formed on the base layer by epitaxial growth or ion implantation;
- forming a strip-shaped trench having a longitudinal direction and reaching the drift layer by penetrating the source region and the base layer;
- forming a first conductivity type channel layer on an inner wall of the trench by epitaxial growth;
- forming a gate insulation layer on the channel layer;
- and
- forming a gate electrode on a surface of the gate insulation layer in the trench, wherein
- the preparing the semiconductor substrate includes forming the source region on the base layer by ion implantation in such a manner that the source region is formed at a long side portion of the trench and is not formed at an end portion of the trench in the longitudinal direction.
4 more elements
Dependencies are inferred from the claim text.