Patent ID: 7323402

Claim:
A method for fabricating a trench Schottky rectifier with varying oxide thickness, comprising the steps of: etching a face of a silicon substrate having a first conductivity type to form a plurality of spaced trenches extending downward from the face into the silicon substrate; growing an oxide layer on sidewall and bottom surfaces of each of said plurality of trenches; depositing a trench nitride layer over at least the oxide layer lining the sidewall and bottom surfaces of each of said plurality of trenches; etching the trench nitride layer to expose for each of said plurality of trenches the oxide layer lining at least the bottom surface of the trench; continuing to grow for each of said plurality of trenches the oxide layer lining the bottom surface of the trench; stripping the trench nitride layer to expose for each of said plurality of trenches the oxide layer lining the sidewall surface, thereby forming an oxide layer of varying thicknesses along the sidewall and bottom surfaces respectively of each trench; and forming a Schottky metal layer atop the face of said silicon substrate such that the Schottky metal layer forms a Schottky rectifier contact in mesa regions between the plurality of trenches.