Abstract: A method for manufacturing a SiC mixed trench Schottky diode may include steps of providing a substrate and an epitaxial layer on top of the substrate; forming a plurality of trenches on a surface of the epitaxial layer; conducting ion implantation at a bottom portion of each trench; conducting ion implantation at sidewalls of each trench; forming an ohmic contact metal at a bottom portion of the Schottky diode; forming a Schottky contact metal on top of the epitaxial layer and in the trenches. In one embodiment, the substrate is an N+ type SiC and the epitaxial layer is an N? type SiC. In another embodiment, the step of forming a plurality of trenches on a surface of the epitaxial layer may include the step of etching the surface of the epitaxial layer by either dry etching or wet etching.

Abstract: A method for manufacturing a SiC mixed trench Schottky diode may include steps of providing a substrate and an epitaxial layer on top of the substrate; forming a plurality of trenches on a surface of the epitaxial layer; conducting ion implantation at a bottom portion of each trench; conducting ion implantation at sidewalls of each trench; forming an ohmic contact metal at a bottom portion of the Schottky diode; forming a Schottky contact metal on top of the epitaxial layer and in the trenches. In one embodiment, the substrate is an N+ type SiC and the epitaxial layer is an N? type SiC. In another embodiment, the step of forming a plurality of trenches on a surface of the epitaxial layer may include the step of etching the surface of the epitaxial layer by either dry etching or wet etching.

Abstract: A method for manufacturing a Silicon Carbide (SiC) Schottky diode may include steps of providing a substrate; forming a first epitaxial layer with a first conductivity type on top of the substrate; forming a second epitaxial layer with a second conductivity type on top of the first epitaxial layer; forming a third epitaxial layer with the second conductivity type on top of the second epitaxial layer; patterning and etching the second and third epitaxial layers to form a plurality of trenches; depositing a first ohmic contact metal on a backside of the substrate; forming a second ohmic contact metal on top of the second epitaxial layer; forming a Schottky contact metal at a bottom portion of each trench; and forming a pad electrode on top of the Schottky contact metal.

Abstract: In one aspect, a method for nickel etching may include steps of depositing a nickel metal layer on a substrate; pattering a photoresist layer on the nickel metal layer; oxidizing the nickel metal layer that is not covered by the photoresist layer to form an oxidized nickel metal layer; and removing the photoresist layer; and etching the nickel metal layer using the oxidized nickel metal layer as a mask. An image reverse technique is used here to form the oxidized nickel metal layer because the oxidized nickel metal layer is resistant to wet etching etchants, so the oxidized nickel metal layer can be used as a real mask for etching.

Abstract: In one aspect, a method for manufacturing a Schottky diode with double P-type epitaxial layers may include steps of: providing a substrate; forming a first epitaxial layer on top of the substrate; forming a second epitaxial layer on top of the first epitaxial layer; depositing a third epitaxial layer on top of the second epitaxial layer; patterning the second and third epitaxial layers to form a plurality of trenches in the second and third epitaxial layers; depositing a first ohmic contact metal on a backside of the substrate; forming a second ohmic contact metal on top of the patterned third epitaxial layer; forming a Schottky contact metal at a bottom portion of each trench; and forming a pad electrode on top of the Schottky contact metal. In one embodiment, the second and third epitaxial layers can be made by P? type SiC and P+ type SiC, respectively.

Abstract: A passivation method for a silicon carbide (SiC) surface may include steps of providing a silicon carbide surface, depositing a thin metal layer on the silicon carbide surface, forming a first passivation layer on the metal layer at low temperature, and generating a dielectric layer by a reaction between a gas/liquid ambient and the thin metal layer. In one embodiment, the thin metal layer is deposited on the silicon carbide surface by sputtering, e-beam evaporation, electroplating, etc. In another embodiment, the metal may include, but not limited to, aluminum, magnesium, etc. In a further embodiment, the passivation layer can be a low temperature oxide and/or nitride layer. In still a further embodiment, the dielectric layer can be aluminum oxide, titanium di-oxide etc. The passivation method for a silicon carbide (SiC) may further include a step of forming a second passivation layer on the first passivation layer.

Abstract: In one aspect, a method for manufacturing a Schottky diode may include steps of providing a substrate, depositing an epitaxial layer on top of the substrate, forming one or more trenches on top of the epitaxial layer, producing an implantation region at a bottom portion of each trench, providing an ohmic contact metal on an opposite site of the substrate, and depositing a Schottky contact metal on top of the epitaxial layer and filled into each trench to form a Schottky junction between the Schottky contact metal and the epitaxial layer, and between each trench and the epitaxial layer. In one embodiment, the substrate is made by N+ type Silicon Carbide (SiC) and the epitaxial layer is made by N? type SiC. In another embodiment, the step of producing an implantation region includes a step of doping P-type impurity into the bottom of each trench.

Abstract: In one aspect, a method of manufacturing a trench type Schottky diode may include steps of providing a substrate, depositing an epitaxial layer on top of the substrate, forming one or more trenches on top of the epitaxial layer, forming a first implantation region in a bottom portion of each trench, forming a second implantation region in a sidewall portion of the trench, depositing an ohmic contact metal on an opposite side of the substrate, and depositing a Schottky contact metal on top of the epitaxial layer and filling the Schottky contact metal in each trench. In one embodiment, the substrate is made by an N+ type SiC, and the epitaxial layer is made by an N-type SiC on top of the substrate. In another embodiment, the first implantation region can be doped with P-type impurity and the second implantation region can be doped with N-type impurity.

Abstract: A method for fabricating a silicon carbide power device may include steps of: forming a first n-type silicon carbide layer on top of a second n-type silicon carbide layer; depositing a first metal layer on the first silicon carbide layer; patterning the first metal layer; depositing and patterning a dielectric layer onto at least a portion of the pattered first metal layer; and depositing and patterning a second metal layer to form a Schottky barrier. In one embodiment, the first metal layer is a high work function metal layer, which may include Silver, Aluminum, Chromium, Nickle and Gold. In another embodiment, the second metal layer is called a “Schottky metal” layer, which may include Platinum, Titanium and Nickle Silicide.

Abstract: A passivation method for a silicon carbide (SiC) surface may include steps of providing a silicon carbide surface, depositing a thin metal layer on the silicon carbide surface, forming a first passivation layer on the metal layer at low temperature, and generating a dielectric layer by a reaction between a gas/liquid ambient and the thin metal layer. In one embodiment, the thin metal layer is deposited on the silicon carbide surface by sputtering, e-beam evaporation, electroplating, etc. In another embodiment, the metal may include, but not limited to, aluminum, magnesium, etc. In a further embodiment, the passivation layer can be a low temperature oxide and/or nitride layer. In still a further embodiment, the dielectric layer can be aluminum oxide, titanium di-oxide etc. The passivation method for a silicon carbide (SiC) may further include a step of forming a second passivation layer on the first passivation layer.