Polycrystalline silicon thin film preparation method

Abstract

The invention discloses a preparation method for a polycrystalline silicon film, which relates to a manufacturing technology in the semiconductor field. The preparation method comprises the following steps that: steps for depositing the polycrystalline silicon film are divided into at least two steps, and a treatment step of assistant gas is performed between each two steps to inhibit the growth of crystal grains. The assistant gas can be nitrogen or hydrogen or helium gas. Compared with the prior art, the crystal grains of the polycrystalline silicon film produced by the preparation method are smaller, which can effectively reduce the penetration of implanted ions to a semi-conductor substrate during the subsequent ion implantation process to the polycrystalline silicon film, and effectively improve the accuracy of characteristic dimension during the subsequent process of etching the polycrystalline silicon film, thereby reducing the attenuation of the performance of a semiconductor device.

Description

technical field [0001] The invention relates to the manufacturing technology in the semiconductor field, in particular to a method for preparing a polysilicon film used as a gate on a semiconductor device. Background technique [0002] Semiconductor devices generally include a semiconductor silicon substrate, a gate oxide layer (usually silicon dioxide, or silicon nitride, etc.) on the substrate, and a polysilicon film deposited on the gate oxide layer, wherein the polysilicon film is the semiconductor device. grid. With the development of semiconductor technology, the operating speed of semiconductor devices is getting faster and faster, the integration of chip circuits is getting higher and higher, and the power consumption is getting lower and lower, so that the characteristic size of the polysilicon gate of the semiconductor device (critical dimension, CD), the thickness of the gate oxide layer and other parameters gradually become smaller, so that it is easier to form ...

AI Technical Summary

Problems solved by technology

Since the structure of the undoped polysilicon film is a typical columnar grain, in the process of ion implantation, because the ion implantation concentration is generally high, the implanted ions can easily penetrate into the semiconductor substrate through the grain boundary edge of the polysilicon film, causing the semiconductor substrate The change of channel ion dose will lead to the attenuation of the performance of semiconductor devices and reduce the yield

Images