Double-diffused metal oxide transistor manufacturing method and transistor device

Abstract

The invention provides a double-diffusion metal oxide transistor manufacture method and a double-diffusion metal oxide transistor device. The double-diffusion metal oxide transistor manufacture method includes the following steps that: a gate oxide layer is grown on the surface of an N type silicon semiconductor epitaxial layer, and a polycrystalline silicon layer is deposited on the surface of the N type silicon semiconductor epitaxial layer, and a polycrystalline silicon window is formed on the polycrystalline silicon layer; a doping element is injected into the N type silicon semiconductor epitaxial layer through the polycrystalline silicon window, so that P type body regions can be formed; an N type doping element is injected into the P type body regions through the polycrystalline silicon window, so that source regions can be formed; a P type doping element is injected into the polycrystalline silicon window for a first time, so that P type well regions can be formed between the plurality of source regions; a dielectric layer is deposited on the substrates of the P type well regions; source contact holes in the region of the polycrystalline silicon window are opened, and part of silicon oxide in the contact holes is removed; and the P type doping element is injected into the contact holes for a second time, so that the junction depth of the P type well regions can be increased. With the double-diffusion metal oxide transistor manufacture method and the double-diffusion metal oxide transistor device adopted, the cellular structure of the transistor can be optimized, and the base resistance of the transistor can be decreased, and the transistor can have better anti-avalanche impact ability.

Description

Technical field [0001] The invention relates to the field of semiconductor devices and their process manufacturing, in particular to a method for manufacturing a double diffused metal oxide transistor and a double diffused metal oxide transistor device. Background technique [0002] With the extensive use of power adapters, inverters, HID lighting, LED drivers and other circuits, semiconductor transistors are also used more and more, in DMOS (Double-diffused Metal Oxide Semiconductor) In the manufacturing field, with the increasingly fierce market competition, it is becoming more and more important to continuously improve the reliability of the device, and the EAS (Energy Avalanche Stress, single pulse avalanche breakdown energy) capability is an important indicator to measure the robustness of DMOS devices. , It is a parameter that characterizes the avalanche resistance of the device. The stronger the EAS ability, the better the reliability. [0003] In the prior art, the P+ (hea...

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Problems solved by technology

figure 2 R shown in b is the equivalent resistance of the base area. Although the emitter area of ​​the parasitic tube has been short-circuited with the base area in design, if the avalanche current is large enough, once R b The voltage drop on the drop exceeds 0.7V, at this time the V of the parasitic tube BE The junction will still be forward-conducting, so that the parasitic tube will be turned on, and the DMOS tube will lose control. Excessive continuous current will cause the junction temperature inside the device to rise rapidly, and even burn the device directly in severe cases, resulting in EAS failure.

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