Groove-type Schottky diode and manufacture method thereof

A technology of Schottky diodes and manufacturing methods, applied in semiconductor/solid-state device manufacturing, electrical components, circuits, etc., can solve problems such as fault generation and easy faults, and achieve short reverse recovery time and low reverse voltage leakage current , The effect of high reverse withstand voltage value

CN101609801AActive Publication Date: 2009-12-23PFC DEVICE HLDG
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2009-12-23

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Abstract

The invention discloses a groove-type Schottky diode and a manufacture method thereof. The method comprises the following steps of: providing a semiconductor substrate; forming a first mask layer on the semiconductor substrate; forming a multi-groove structure in the semiconductor substrate; forming a gate oxide layer on the surface of the multi-groove structure; forming a polysilicon structure on the gate oxide layer and the first mask layer; etching the polysilicon structure; forming a second mask layer on the part of the polysilicon structure and the part of the first mask layer; forming a metal sputtering layer on the second mask layer and the partial surfaces of the semiconductor substrate, the polysilicon structure and the gate oxide layer; and etching the metal sputtering layer. The structure of the groove-type Schottky diode can be effectively isolated from an external environment, and has lower backward voltage leakage current, lower forward bias voltage, higher backward voltage resistant value and shorter backward recovery time.
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Description

technical field

[0001] The present invention relates to a trench Schottky diode and its manufacturing method, in particular to a manufacturing method to provide a low reverse voltage leakage current, low forward bias voltage (Vf), low Trench Schottky diode with high reverse withstand voltage and short reverse recovery time (tRR). Background technique

[0002] Schottky Diode is a unipolar element that uses electrons as carriers. It is characterized by fast speed, and when a lower forward bias voltage (Forward Bias Voltage; Vf) is added, it can There is a larger forward current and a shorter reverse recovery time (Reverse Recovery Time; tRR), but if a continuously increasing reverse bias is added, there will be a larger leakage current (compared to the metal work function and semiconductor The Schottky barrier (Schottky Barrier) caused by the doping concentration). Then, a trench-type Schottky barrier diode was proposed. By filling the trench with polysilicon or metal to pin...

Examples

Embodiment Construction

[0029] see Figure 2(a) to Figure 2(o) , is a schematic diagram of the fabrication process of a preferred embodiment of the trench Schottky diode fabrication method proposed by the present invention. As shown in Figure 2 (a), at first a semiconductor substrate 30 is provided; Type) epitaxial layer 32 two parts; Wherein the epitaxial layer 32 of low doping concentration is formed on the silicon substrate 31 of high doping concentration, and the epitaxial layer 32 of its low doping concentration has certain thickness, to provide this The etching formation of the multi-trench structure (Multi-Trench) required for the subsequent invention.

[0030] Then on the surface 32a of the semiconductor substrate 30, that is, the surface 32a where the epitaxial layer 32 of low doping concentration is located, a thermal oxidation (Thermal Oxidation) process is first carried out, and on the surface 32a of the semiconductor substrate 30 A first oxide layer 41 is formed; in this embodiment, th...