US 8,264,036 B2 · Power semiconductor device with low on-state voltage and method of manufacturing the same

Abstract

A semiconductor device according to the invention includes n-type semiconductor substrate 1; trenches 15 formed in the surface portion of semiconductor substrate 1; a protruding semiconductor region between trenches 15; p-type base layer 2 in the protruding semiconductor region, p-type base layer 2 being positioned as deep as or shallower than trench 15; an n++-type emitter region or a source region in the surface portion of p-type base layer 2; gate insulator film 4a on the first side wall of the protruding semiconductor region; and gate electrode 6 on gate insulator film 4a. Trench 15 is from 0.5 μm to 3.0 μm deep and the short side of trench 15 is 1.0 μm or longer. The short side of the protruding semiconductor region is from 0.5 μm to 3.0 μm long. Gate electrode 6 contains electrically conductive polycrystalline silicon as its main component. Gate electrode 6 is from 0.2 μm to 1.0 μm thick. The semiconductor device according to the invention is manufactured with very low manufacturing costs and with a high throughput of non-defective products. The semiconductor device according to the invention facilitates exhibiting a high IE effects, exhibiting a low ON-state voltage, preventing electric field localization from causing and realizing a high breakdown voltage.

Claims17

Dependent claims

A semiconductor device comprising:

a semiconductor substrate of a first conductivity type comprising a first major surface;
at least one pair of trenches extending in parallel to each other and formed from the first major surface;
a protruding semiconductor region between the pair of trenches, the protruding semiconductor region being narrower than the trenches;
a base layer of a second conductivity type in the protruding semiconductor region;
a region of the first conductivity type on a surface side of the base layer;
a gate insulator film on a first side wall of the protruding semiconductor region;
a gate electrode on the gate insulator film;
the protruding semiconductor region being from 0.5 μm to 3.0 μm in short side width;
the trench being from 0.5 μm to 3.0 μm in depth;
the trench being 1.0 μm or longer in short side width;
the trench being wider than the protruding semiconductor region in the short side widths thereof;
the gate electrode comprising electrically conductive polycrystalline silicon as a main component thereof;
and
the gate electrode being from 0.2 μm to 1.0 μm in thickness.

11 more elements

The method of manufacturing the semiconductor device comprising:

forming a semiconductor substrate of a first conductivity type comprising a first major surface;
forming at least one pair of trenches extending in parallel to each other and formed from the first major surface;
each trench being from 0.5 um to 3.0 um in depth and 1.0 um or longer in short side width such that there is a protruding semiconductor region between the pair of trenches, the protruding semiconductor region being narrower than the trenches' and being from 0.5 um to 3.0 um in short side width with the trench being wider than the protruding semiconductor region in the short side width thereof;
forming a base layer of a second conductivity type in the protruding semiconductor region;
forming a region of the first conductivity type on a surface side of the base layer;
forming a gate insulator film on a first side wall of the protruding semiconductor region;
forming a gate electrode comprising electrically conductive polycrystalline silicon as a main component thereof on the gate insulator film;
the gate electrode being from 0.2 um to 1.0 um in thickness the that there are protruding semiconductor regions.

5 more elements

Dependencies are inferred from the claim text.

Power semiconductor device with low on-state voltage and method of manufacturing the same

Life of this patent

Power semiconductor device with low on-state voltage and method of manufacturing the same

Life of this patent

Abstract

Claims17