Composite trench MOS device and manufacturing method thereof

Abstract

The invention belongs to the technical field of semiconductor power devices and specifically relates to a composite trench MOS device and a manufacturing method thereof. A Schottky diode structure anda TMBS structure are integrated in a contact hole of each trench MOSFET unit cell, Schottky contact is formed at a side wall of a contact hole of the trench MOSFET unit cell, a switching loss is reduced and spike voltage and spike current are suppressed, and a reverse recovery characteristic is improved. The TMBS structure is formed at the bottom of the contact hole, a balanced electric field canbe formed in the device, the breakdown characteristics of the device are improved, thus while the performance of the device is improved, a silicon surface area is effectively saved, and the cost of achip is reduced. The composite trench MOS device has the advantages of a simple manufacturing process, low cost, a novel structure and high product performance and reliability, peak voltage and peakcurrent of trench MOSFET device reverse recovery can be effectively suppressed, and the voltage withstanding performance of the device is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor power devices, in particular to a composite trench MOS device structure and a manufacturing method thereof. Background technique [0002] With the continuous and rapid development of my country's economy, energy consumption is also increasing year by year, especially in the context of global warming, "low-carbon economy" has gradually become a global hotspot, so energy conservation has become one of my country's basic national policies. The new power electronic devices play a particularly important role in it. Among them, the trench MOS device is a semiconductor device with rapid development and good market prospects. It has fast switching speed, high input impedance, good thermal stability and strong reliability. It has a wide range of applications in the fields of computers, communication equipment, power supply circuits of general office equipment, and automotive electronic circuits. [...

AI Technical Summary

Problems solved by technology

The disadvantage is still high cost, high requirements for packaging, and large overall area after packaging

[0006] The third stage is to design and manufacture trench MOSFETs and Schottky diodes in the same chip. The method of processing trench MOSFETs and Schottky diodes is to use partition design and differentiated manufacturing schemes, and realize through wire bonding. Interconnection still occupies a large amount of chip area and cost

Therefore, the disadvantages are always: 1. The Schottky diode structure occupies a large amount of silicon surface area, resulting in large chip area and high cost; 2. The process is complicated, resulting in high manufacturing cost.

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