Trench type Schottky diode

Abstract

A trench type Schottky diode includes a substrate, an n type epitaxial layer, a metal layer, a plurality of oxide layers, a first electrode connected with the substrate and a second electrode connected with the epitaxial layer. The epitaxial layer is located on the substrate and includes a plurality of trenches. The metal layer includes a plurality of metal trench-filling parts located in the trenches respectively, and a material work function of the metal layer is larger than or equal to 4.8 electron volts. The oxide layers are located in the trenches respectively and located between each metal trench-filling part and the epitaxial layer respectively. Metal layer materials having a high work function are filled in the trenches, thereby enabling the trench type Schottky diode to have a relatively good forward bias characteristic. Thus, the trench type Schottky diode has a good forward bias characteristic while being capable of bearing high reverse bias, and also keeps the advantage of rapid switching of a Schottky element.

Description

technical field [0001] The invention relates to a diode, in particular to a trench Schottky diode combined with a Schottky junction. Background technique [0002] refer to figure 1 , is an existing trench Schottky diode, comprising: a substrate 11, an epitaxial layer 12 located on the substrate 11, several semiconductor layers 13, several oxide layers 14, a first electrode 15, and a second electrode 16 . The substrate 11 is an n-type silicon substrate. The epitaxial layer 12 is an n-type semiconductor, and has a plurality of trenches 121 spaced apart from each other and recessed downward from its top surface. The semiconductor layer 13 fills the trenches 121 respectively, and its material is n-type polysilicon. The oxide layers 14 are respectively located in the trenches 121 , and are respectively located between each semiconductor layer 13 and the epitaxial layer 12 . The first electrode 15 is located on the bottom surface of the substrate 11 . The second electrode 16...

AI Technical Summary

Problems solved by technology

However, it has been found in practice that when the trench Schottky diode with the above structure is fabricated as a component that can withstand a relatively high reverse bias voltage (that is, has a high breakdown voltage (BreakdownVoltage)), its forward bias characteristic will change. difference, in other words, the forward bias required to produce the same current must be increased

Therefore, the trench Schottky diode needs to be improved

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