NMOS transistor, making method thereof, and CMOS transistor

Abstract

The present invention provides a method for making an NMOS transistor. The method comprises a step of forming a light shielding layer and a buffer layer which covers the light shielding layer on a substrate, a step of forming a polysilicon layer on the buffer layer, wherein the polysilicon layer comprises a middle part, two first end parts and two second end parts, a step of carrying out a first time of ion implantation on the first end parts and the second end parts, a step of carrying out a second time of ion implantation on the first end parts, a step of forming a first insulation layer which covers the polysilicon layer on the buffer layer, a step of forming a gate on the first insulation layer, a step of forming a second insulation layer which covers the gate on the first insulation layer, and a step of forming a source electrode and a drain electrode on the second insulation layer, wherein the source electrode is in contact with one of two first end parts, and the drain electrode is in contact with the other end of the two first end parts. The reflow characteristic of a photoresist is used to make an N type heavily doped region and an N type lightly doped region, thus the pass-through of the first insulation layer in ion implantation is not needed, the damage of the first insulation layer is reduced, and the symmetry of the N type heavily doped region and the symmetry of the N type lightly doped region are good.

Description

technical field [0001] The invention relates to a manufacturing process of a MOS transistor, in particular to an NMOS transistor, a manufacturing method thereof, and a CMOS transistor. Background technique [0002] With the evolution of optoelectronics and semiconductor technology, it has also led to the vigorous development of flat panel displays. Among many flat panel displays, liquid crystal displays (LCD for short) have high space utilization efficiency and low power consumption. , no radiation and low electromagnetic interference and many other superior features have become the mainstream of the market. [0003] At present, amorphous silicon thin-film transistors (a-Si TFT) are widely used as switching elements of LCDs, but a-SiTFT LCDs meet the requirements of thin, light weight, high precision, high brightness, high reliability, low power consumption, etc. Requests are still limited. Compared with a-Si TFT LCD, low temperature polycrystalline silicon (Lower Temperat...

AI Technical Summary

Problems solved by technology

However, in the LTPS process of the current technology, ions need to pass through the gate insulating layer during the ion implantation process, which will cause damage to the gate insulating layer, and the symmetry of the N-type heavily doped region and the N-type lightly doped region will be formed. The symmetry of the doped regions is poor

Images