Power device with high-voltage radio-frequency lateral diffusion structure and production method of power device

Abstract

The invention provides a power device with a high-voltage radio-frequency lateral diffusion structure and a production method of the power device. The production method comprises the steps of providing a P-type substrate, on which a P-type epitaxial layer is arranged; forming a P-type depressed region and a plurality of local oxide isolations on the epitaxial layer; thermally growing gate oxide and phosphor-doped polycrystalline silicon gate to form a grid; respectively filling boron on the two sides of the grid to form a P-type body region, filling phosphor to form an N-type drift region, push-connecting the P-type body region with the N-type drift region at high temperature; respectively filling boron in the P-type depressed region to form a P+ region, filling arsenic in the P-type body region and the N-type drift region to form an N+ region and annealing at high temperature; generating an oxide-nitride-oxide (ONO) structure on the surface of a device, etching through a dry process and obtaining D-shaped side walls on the two sides of the grid; removing silicon dioxide on the surfaces of the side walls and obtaining L-shaped side walls; forming a barrier layer on the surface of the device and opening a window above the grid; and forming titanium silicide contact above the grid. The power device with the high-voltage radio-frequency lateral diffusion structure and the production method of the power device have the advantages that the risks that the source is short-circuited with the drain can be effectively avoided, the grid silicide with very low resistivity can be obtained and the demands of high-frequency lateral diffusion metal-oxide-semiconductor field-effect transistors (LDMOS) can be met.

Description

technical field [0001] The invention relates to the technical field of semiconductor device manufacturing, in particular, the invention relates to a power device with a high-voltage radio frequency lateral diffusion structure and a manufacturing method thereof. Background technique [0002] Power devices with high-frequency lateral diffusion structure (Lateral Diffusion MOSFET, LDMOS for short) (frequency range 2.11GHz ~ 2.17GHz, breakdown voltage ≥ 70V, output power 30W) are widely used in 3G communication radio frequency base stations, radar, digital TV, etc. . High-performance high-frequency LDNMOS not only requires high voltage resistance and high drive current, but also has higher requirements for frequency, so the research on its related technology is a hot research field in recent years. [0003] The resistance of polycrystalline gate is a very important parameter of high-frequency LDNMOS. The traditional polycrystalline silicide is tungsten silicide (WSix). The proc...

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Problems solved by technology

[0003] The resistance of polycrystalline gate is a very important parameter of high-frequency LDNMOS. The traditional polycrystalline silicide is tungsten silicide (WSix). The process is simple, but the resistivity of tungsten silicon is relatively large (greater than 6ohm / sqr), and the high-stress chemical vapor phase Fluorine, a by-product of deposition (CVD), may diffuse into the gate oxide, degrading the quality of the gate oxide and risking poor reliability

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