A kind of finfet and preparation method thereof

Abstract

The invention provides an FinFET and a preparation method thereof. Trenches among adjacent fin-shaped structures form shallow trench isolation structures (STI), and oxide layers and insulation material layers are arranged among shallow trenches, the fin-shaped structures and a substrate, so that isolation effect can be achieved well, and diffusion of doping-ions in the fin-shaped structures and the substrate can be avoided; iron injection of high dose C-co or high dose F-co in the conventional FinFET preparation process can be avoided, so that the damage to the substrate and the fin-shaped structures due to the bombardment effect during iron injection can be reduced; and furthermore, the form of an SSRW also can be maintained well, the carrier mobility can be effectively improved, and the performance of the device can be greatly improved.

Description

technical field [0001] The invention relates to a method for preparing a semiconductor, to be precise, relates to a FinFET and a method for preparing the same. Background technique [0002] Field Effect Transistor (Field Effect Transistor, FET) is conducted by majority carriers, and is also called unipolar transistor. It is a voltage-controlled semiconductor device. It has the advantages of high input resistance, low noise, low power consumption, large dynamic range, easy integration, no secondary breakdown phenomenon, and wide safe working area, and is widely used in the field of semiconductor preparation. With the continuous maturity of FET technology and people's continuous pursuit of high-performance devices, Professor Hu Zhengming of the University of California, Berkeley developed a new type of field effect transistor—FinFET (Fin Field Effect Transistor). In the structure of FinFET, the gate Formed into a fork-shaped 3D structure similar to a fish fin, it can control...

AI Technical Summary

Problems solved by technology

At present, a SSRW (Super Steep Retrograde Well) technology has been developed to effectively improve carrier mobility, but this technology has only been widely used in planar FETs, but it is still difficult to SSRW technology is perfectly applied to the preparation of FinFET

This is because in the FinFET, if the width of the raised fin structure (Fin) is too small, the ions implanted into the FinFET are easily diffused into the shallow trench during the heat treatment process during the SSRW ion implantation process. Isolation structure (STI, Shallow Trench Isolation), resulting in a certain loss of dopant dose, especially in the oxygen-enhanced diffusion process, the diffusion is more serious, after many times of doping and heat treatment, the diffusion phenomenon will become more and more serious , and then affect the morphology of SSRW, so that the performance of the device is well improved

Images