The invention provides a trench barrier MOS
Schottky diode device made of a high-
dielectric-constant gate medium material. The trench barrier MOS
Schottky diode device comprises an N+
semiconductor substrate, an N- epitaxial layer on the N+
semiconductor substrate, a trench structure formed in the N- epitaxial layer,
anode metal and
cathode metal, wherein the
anode metal is located on the N- epitaxial layer, Schottky contact grows in a trench, the
cathode metal is located under the N+
semiconductor substrate, and
Ohmic contact grows in the
cathode metal. An oxidation layer on the side wall of the trench comprises the upper portion and the lower portion, the upper portion is made of the high-
dielectric-constant gate medium material, and the lower portion is made of
silicon dioxide. The height of the portion, where the high-
dielectric-constant gate medium material grows, of the inner wall of the trench is within three fourths of the total height of the trench. According to the trench barrier MOS
Schottky diode device made of the high-dielectric-constant gate medium material, the upper portion of the oxidization layer in the trench is made of the high-dielectric-constant gate medium material, the lower portion is made of the
silicon dioxide, compared with a traditional SiO2TMBS device, the
leakage current density can be reduced by 19.8%, and the
breakdown voltage and forward conductive
voltage characteristics of the device are not weakened.