Trench Schottky rectifier device and method for manufacturing the same

A method for fabricating a trench Schottky rectifier device, comprising steps of:

• providing a substrate having a first conductivity type;
• forming a mask oxide layer on the substrate and forming a plurality of openings in the mask oxide layer;
• forming a first plurality of trenches and a second plurality of trenches in the substrate according to the plurality of openings in the mask oxide layer;
• forming a plurality of doped regions having a second conductivity type in the substrate under the first plurality of trenches and the second plurality of trenches;
• forming an insulating layer on sidewalls of the first plurality of trenches and the second plurality of trenches;
• remaining a first portion of the mask oxide layer to cover a first portion of the substrate and removing a second portion of the mask oxide layer to expose a second portion of the substrate;
• forming an adhesion layer on the first portion of the mask oxide layer, the second portion of the substrate, the insulating layer, bottoms of the first plurality of trenches and the second plurality of trenches;
• filling the first plurality of trenches with a first plurality of conductive structures and filling the second plurality of trenches with a second plurality of conductive structures;
• forming an electrode overlying the adhesion layer, the first plurality of conductive structures and the second plurality of conductive structures;
• forming a patterned photoresist layer over the electrode;
• etching off portions of the electrode and an adhesion layer according to the patterned photoresist layer;
• removing the patterned photoresist layer;
• and
• wherein the adhesion layer disposed between the first portion of the mask oxide layer and the electrode on the first portion of the substrate and disposed between the electrode and the second plurality of conductive structures on the second portion of the substrate.