Manufacturing method of active area of DMOS device and the DMOS device

Abstract

An embodiment of the invention discloses a manufacturing method of an active area of a double-diffusion metallic oxide semiconductor DMOS device and the DMOS device. The method is characterized by forming an N-type epitaxial layer, a gate oxide layer and a doped polysilicon layer on an N-type substrate and forming a gate area and a groove; forming a P-type body area in the N-type epitaxial layer and forming an N-type source area in the P-type body area; etching to form a schottky contact area; and depositing a metal layer, forming the schottky contact region in the schottky contact area, and forming a source electrode and a drain electrode. In the embodiment of the invention, the schottky contact regions are formed in the metal layer and the N-type epitaxial layer. When the DMOS device works in a positive conduction state, storage charges in a drift region and reverse recovery charges are reduced. When the DMOS device is in a reverse blocking-up state, a schottky contact electric field is reduced, and a schottky contact breakdown voltage is increased and a leakage current is reduced so that the DMOS device satisfies breakdown voltage and electric leakage requirements during an application process.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing an active region of a DMOS device and a DMOS device. Background technique [0002] A DMOS device is a type of MOSFET that uses diffusion to form the transistor region. MOSFET is a widely used power switching device, which has the advantages of high input impedance, low loss, fast switching speed, no secondary breakdown, wide safe working area, and good dynamic performance. [0003] In some existing power switching circuits that require reverse current to flow through active switching devices, MOSFETs must conduct in reverse, for example, DC to AC inverter switching power supplies for speed-adjustable motor drives, and for motors Controlled, DC converter with regenerative braking, etc. [0004] However, the lifetime of the drift region of the MOSFET device manufactured by the traditional process is relatively long, and there is a large amount of...

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Problems solved by technology

[0006] Embodiments of the present invention provide a method for fabricating an active region of a DMOS device and a DMOS device, which are used to solve the problem that the DMOS device manufactured by the prior art exhibits a relatively low switching speed due to a long reverse recovery time, resulting in various problems. technical problem

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