Silicon carbide semiconductor device and method of manufacturing silicon carbide semiconductor device
AssigneeFuji Electric Co., Ltd.
InventorsMakoto UTSUMI, Akimasa KINOSHITA
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Abstract
A trench gate structure vertical MOSFET includes a silicon carbide substrate of a first conductivity type, a first semiconductor layer of the first conductivity type, a second semiconductor layer of a second conductivity type, first semiconductor regions of the first conductivity type, a trench, a gate electrode, an interlayer insulating film, a barrier layer, a contact electrode, a first electrode, and a second electrode. The barrier layer includes a layer made of TiN, and the thickness of the TiN layer is 10 to 80 nm. The interlayer insulating film is a laminate film of non-doped silicate glass and borophosphosilicate glass.
Claims13
A silicon carbide semiconductor device, comprising:
- a silicon carbide substrate of a first conductivity type;
- a first semiconductor layer of the first conductivity type, provided on or over a front surface of the silicon carbide substrate;
- a second semiconductor layer of a second conductivity type, provided on the first semiconductor layer on a side opposite to the silicon carbide substrate;
- first semiconductor regions of the first conductivity type, selectively provided in a top surface of the second semiconductor layer;
- a trench penetrating through the second semiconductor layer and the first semiconductor regions and reaching the first semiconductor layer;
- a gate electrode provided inside the trench with a gate insulating film interposed therebetween;
- an interlayer insulating film covering the gate electrode;
- a layer made of TiN covering the interlayer insulating film;
- a contact electrode contacting the second semiconductor layer;
- a first electrode over the layer made of TiN, electrically connecting to the contact electrode and the first semiconductor regions;
- and
- a second electrode provided on a rear surface of the silicon carbide substrate,
- wherein a film thickness of the layer made of TiN is 10 to 80 nm, and
- wherein the interlayer insulating film is a laminate film of a layer of non-doped silicate glass and a layer of borophosphosilicate glass.
A method of manufacturing a silicon carbide semiconductor device, the method comprising:
- a first step of forming a first semiconductor layer of a first conductivity type on or over a front surface of a silicon carbide substrate of the first conductivity type;
- a second step of forming a second semiconductor layer of a second conductivity type on the first semiconductor layer on a side opposite to the silicon carbide substrate;
- a third step of selectively forming first semiconductor regions of the first conductivity type in a top surface of the second semiconductor layer;
- a fourth step of forming a trench penetrating through the second semiconductor layer and the first semiconductor regions and reaching the first semiconductor layer;
- a fifth step of forming a gate electrode inside the trench with a gate insulating film interposed therebetween;
- a sixth step of forming an interlayer insulating film covering the gate electrode;
- a seventh step of forming a layer made of TiN covering the interlayer insulating film;
- an eighth step of forming a contact electrode contacting and the second semiconductor layer;
- a ninth step of forming a first electrode over the layer made of TiN, electrically connecting to the contact electrode and the first semiconductor regions;
- and
- a tenth step of forming a second electrode on a rear surface of the silicon carbide substrate,
- wherein in the seventh step, the layer made of TiN is formed to have a film thickness of 10 to 80 nm, and
- wherein in the sixth step, the interlayer insulating film is formed of a laminate film of a layer of non-doped silicate glass and a layer of borophosphosilicate glass.
Dependencies are inferred from the claim text.