Silicon carbide MOSFET device and manufacturing method thereof
View Patent ↗Disclosed a silicon carbide MOSFET device and manufacturing method thereof. The method includes: forming a patterned first barrier layer on an upper surface of the substrate; forming a base region of a second doping type extending from the upper surface to an inside of the substrate through oblique implantation in a first ion implantation process by using a first barrier layer as a mask; forming a source region of the first doping type in the substrate; forming a contact region of the second doping type in the substrate; and forming a gate structure, an implantation angle of the first ion implantation process is adjusted so that the base region extends below a part of the first barrier layer. The method of the present disclosure not only reduces one photoetching process and saves cost, but also realizes a short channel and reduces an on-resistance of the device.
1. A manufacturing method of a silicon carbide MOSFET device, comprising:
providing a substrate of a first doping type;
forming a patterned first barrier layer on an upper surface of the substrate;
forming a base region extending from the upper surface to an inside of the substrate through oblique implantation in a first ion implantation process by using a first barrier layer as a mask, the base region is of a second doping type;
forming a source region of the first doping type in the substrate;
forming a contact region of the second doping type in the substrate; and
forming a gate structure,
wherein, an implantation angle of the first ion implantation process is adjusted so that the base region extends below a part of the first barrier layer, and the implantation angle of the first ion implantation process is an angle between an implanting direction of the first ion implantation process and the upper surface of the substrate;
wherein a step of forming the contact region comprises:
forming the contact region extending from the upper surface to the inside of the substrate through self-aligned implantation in a second ion implantation process by using the first barrier layer as a mask; and
wherein a width of the contact region is smaller than a width of the base region;
wherein a step of forming the source region comprises:
at least etching part of a thickness of the first barrier layer in a lateral direction;
forming a second barrier layer between the etched first barrier layer; and
forming the source region extending from the upper surface to the inside of the substrate through self-aligned implantation in a third ion implantation process by using the etched first barrier layer and the second barrier layer as a mask,
wherein, a thickness of the etched first barrier layer is smaller than a width of the base region extending below the first barrier layer.
2. The manufacturing method according to claim 1 , wherein a material of the first barrier layer is different from a material of the second barrier layer.
3. The manufacturing method according to claim 1 , wherein the thickness of the etched first barrier layer ranges from 800 to 1200 angstroms.
4. The manufacturing method according to claim 1 , wherein the first barrier layer is etched by an isotropic etching process.
5. The manufacturing method according to claim 1 , wherein removing the etched first barrier layer and the second barrier layer after forming the source region.