Silicon carbide semiconductor device
AssigneeHestia Power Inc.
InventorsCheng-Tyng YEN, Chien-Chung HUNG, Chwan-Ying LEE, Lurng-Shehng LEE
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Abstract
A silicon carbide (SiC) semiconductor device having a metal oxide semiconductor field effect transistor (MOSFET) and integrated with an anti-parallelly connected Schottky diode includes: an n-type substrate, an n-type drift layer, a plurality of doped regions, a gate dielectric layer, a gate electrode, an inter-layer dielectric layer, a plurality of source openings, a plurality of junction openings, a plurality of gate openings, a first metal layer and a second metal layer. The second metal layer at the junction openings forms the Schottky diode.
Claims25
A silicon carbide (SiC) semiconductor device, comprising:
- an n-type substrate, having a first doping concentration;
- an n-type drift layer, disposed on the substrate, having a second doping concentration less than the first doping concentration;
- a plurality of doped regions, disposed at the n-type drift layer, spaced from each other and formed a junction field effect transistor (JFET) region having a third doping concentration therebetween, each of the doped regions comprising a p-well, a heavily doped n-type (n+) region located in the p-well, and a heavily doped p-type (p+) region;
- a gate dielectric layer, disposed on the n-type drift layer;
- a gate electrode, disposed on the gate dielectric layer;
- an inter-layer dielectric layer, disposed on the gate dielectric layer 41 and the gate electrode;
- a plurality of source openings, penetrating through the inter-layer dielectric layer and the gate dielectric layer to a surface portion of the n+ region and the p+ region and are separated by the gate electrode and the inter-layer dielectric layer;
- a plurality of junction openings, penetrating through the inter-layer dielectric layer and the gate dielectric layer to a surface portion of the JFET region and the doped regions are separated by the gate electrode and the inter-layer dielectric layer;
- a plurality of gate openings, penetrating through the inter-layer dielectric layer to a surface portion of the gate electrode;
- a first metal layer, disposed at a bottom of the source openings, formed an Ohmic contact with the surface portion of the n+ region and the p+ region;
- and
- a second metal layer, comprising a first portion and a second portion, wherein the first portion covers the source openings and the junction openings is electrically connected to the first metal layer and forms a Schottky contact with the surface portion of the JFET region, the second portion covers the gate openings and is electrically insulated from the first portion.
The SiC semiconductor device of claim I, wherein the first metal layer comprising a silicide or a combination of suicides of a material selected from a group consisting of nickel, titanium, aluminum, molybdenum and niobium.
A. silicon carbide (SiC) semiconductor device, comprising:
- an n-type substrate, having a first doping concentration;
- an n-type drift layer, disposed on the substrate, having a second doping concentration less than the first doping concentration;
- a plurality of first doped regions and a plurality of second doped regions, disposed at the n-type drift layer, each of the first doped regions comprising a first p-well, a heavily doped n-type (n+) region located in the first p-well, and a first heavily doped p-type (p+) region located in the first p-well and surrounded by the n+ region, each of the second doped regions comprising at least one sub-doped region, wherein a first junction field effect transistor (JFET) region having a third doping concentration formed between each of the first doped regions and the second doped regions and a second junction field effect transistor (JFET) region having a fourth doping concentration formed between each of the sub-doped regions or enclosed by the sub-doped region;
- a gate dielectric layer, disposed on the n-type drift layer;
- a gate electrode, disposed on the gate dielectric layer;
- an inter-layer dielectric layer, disposed on the gate dielectric layer and the gate electrode;
- a plurality of source openings, penetrating through the inter-layer dielectric layer and the gate dielectric layer to a surface portion of the n+ region and the first p+ region and are separated by the gate electrode and the inter-layer dielectric layer;
- a plurality of junction openings, penetrating through the inter-layer dielectric layer and the gate dielectric layer to a surface portion of the second JFET region and the second doped regions are separated by the gate electrode and the inter-layer dielectric layer;
- a plurality of gate openings, penetrating through the inter-layer dielectric layer to a surface portion of the gate electrode;
- a first metal layer, disposed at a bottom of the source openings, formed an Ohmic contact with the surface portion of the n+ region and the first p+ region;
- and
- a second metal layer, comprising a first portion and a second portion, wherein the first portion covers the source openings and the junction openings is electrically connected to the first metal layer and forms a Schottky contact with the surface portion of the second JFET region, the second portion covers the gate openings and is electrically insulated from the first portion.
Dependencies are inferred from the claim text.