Method for making polycrystalline silicon gate

Abstract

The invention provides a method for making a polycrystalline silicon gate. The method comprises the following steps: growing a gate oxidation dielectric layer on a substrate on which a PWELL and / or a NWELL are / is formed and growing a polycrystalline silicon layer on the gate oxidation dielectric layer; carrying out a surface doping process on the polycrystalline silicon layer through an ion implantation method, wherein N-type doping impurity is implanted in an NMOS device and P-type doping impurity is implanted in a PMOS device; adopting a polycrystalline silicon etching process to form a polycrystalline silicon gate on the doped polycrystalline silicon layer; and adopting an atomic oxygen oxidation process to oxidize the polycrystalline silicon gate and forming a compact oxidation layer on the surface of the polycrystalline silicon gate. Therefore, the atomic oxygen oxidation process is adopted to eliminate the effect of inconsistent oxidation rate of the polycrystalline silicon gate due to the doping process and solve the problem that the upper part and the bottom part of the polycrystalline silicon gate are inconsistent in width due to a traditional polycrystalline silicon oxidation process so as to achieve the purpose of improving the shape of the polycrystalline silicon gate.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a polysilicon gate manufacturing method for improving the shape of the polysilicon gate. Background technique [0002] Complementary Metal Oxide Semiconductor (CMOS for short) usually refers to a low power consumption device of a complementary MOS integrated circuit composed of (PMOS transistor and NMOS transistor). In the development process of CMOS semiconductor device manufacturing process, the polysilicon gate process technology can continue to the 32 / 28nm process technology node. With the further shrinking of device size and the further improvement of device performance, new technologies of high dielectric constant dielectric and metal gate are introduced into the semiconductor manufacturing process. At present, the more popular polysilicon gate process technology flow is as follows: figure 1 shown. [0003] see figure 1 , a process method for making a polysili...

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Problems solved by technology

[0010] In order to overcome the above problems, the present invention aims to provide a polysilicon gate manufacturing method to solve the problem of inconsistency in the width of the upper part and the bottom of the polysilicon gate caused by the traditional polysilicon oxidation process, that is, to achieve the purpose of improving the shape of the polysilicon gate

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