Longitudinal super junction double diffusion metal oxide semiconductor field effect transistor with composite dielectric layer and manufacturing method thereof

Abstract

The invention provides a longitudinal super junction double diffusion metal oxide semiconductor field effect transistor with composite dielectric layer (CDL) and manufacturing method thereof. The device forms the CDL composed of a semi-insulating polysilicon layer (SIPOS) and a high dielectric constant (High K) dielectric layer on the side wall of a drift region under a device gate electrode. Whenthe device is turned off, the SIPOS column and the High K dielectric layer have a uniform electric field, and the electric field is modulated to make the electric field in the super junction drift region of the device be evenly distributed. Meanwhile, the CDL and the super junction assist the consumption of the super junction drift region together, the consumption capability of the super junctiondrift region is greatly improved, so that the doping concentration of the drift region of the device is increased, and the conductive resistance of the device is reduced. When the device is turned on, the drift region has a majority carrier accumulation layer on the sidewall, so that the conductive resistance of the device is further reduced.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a trench (Trench) type vertical double-diffused metal oxide semiconductor field effect transistor. Background technique [0002] With the rapid development of power MOSFET devices representing new power semiconductor devices, power semiconductor devices are widely used in computer, lighting, consumer electronics, automotive electronics, industrial drives and other fields. Power semiconductor devices are core devices for green, low power consumption, energy saving and environmental protection. For high-voltage MOSFETs, the high energy efficiency requirements of the power supply are the main factors affecting the future development of products. However, in the field of high-voltage applications of power devices, as the breakdown voltage of the device increases, the thickness of the power VDMOS epitaxial layer increases continuously, and the doping concentration of the drift re...

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Problems solved by technology

[0004] It can be seen that under a certain N-column width, the maximum doping concentration of the N-column is determined, that is, the doping concentration of the superjunction drift region is limited, thus affecting the conduction loss of the device

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