A method for preparing a light drain offset structure

Abstract

The invention provides a preparation method of a drain electrode lightly-offset structure. The preparation method comprises the steps of glass substrate crystallization, P-Si substrate imaging, gate insulation layer film formation and gate layer film formation. The drain electrode lightly-offset structure is formed through the following steps of a gumming step, a half-tone exposure step, a developing step, a first-time metal etching step, a first-time ion implantation step, a photoresist-ashing step, a second-time metal etching step, a demoulding step and a second-time ion implantation step, wherein photoresist is subjected to half-tone exposure and developing, and two times of heavily doped and lightly doped ion implantation steps, the photoresist-ashing step and the two times of metal etching steps are combined, so that a source electrode or drain electrode heavily doped region, a gate lightly doped region and a drain electrode lightly doped region are formed, a drain electrode lightly offset (LDO) structure is formed, a hot carrier effect is effectively relieved, a leakage current is reduced, the drain electrode lightly-doped structure has an easy-to-control size and better processing repeatability and uniformity, the production cost and the bad product rate are reduced, and the reliability of a TFT (Thin Film Transistor) product is improved.

Description

technical field [0001] The invention relates to the field of semiconductor device preparation and display, in particular to a preparation method of a light drain offset structure. Background technique [0002] In the display industry, the leakage characteristics of thin film crystalline silicon (Thin Film Transistor, referred to as TFT) have always been the characteristics that enterprises and R&D personnel pay attention to. If the leakage current of thin film transistor TFT is too large, it will not be able to play a good role in the switching of thin film transistor TFT. characteristic. When the thin film transistor TFT is turned off, a large current still flows. The reason for the leakage current of thin film transistor TFT is mainly the hot carrier effect, especially the high mobility polysilicon Poly-Si, microcrystalline silicon and single crystal silicon-thin film transistor TFT, in the node part with different doping concentration, A large leakage current will be ge...

AI Technical Summary

Problems solved by technology

In this preparation method, the gate layer Gate is used for over-etching. After the gate layer Gate is over-etched, the extra size on both sides is used as the size of the drain lightly doped LDD structure. However, this size is very difficult to control, resulting in poor repeatability and uniformity. , and the over-engraving of the gate layer Gate will cause the slope angle to deteriorate and reduce the reliability of the product

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