Method for improving stability of polysilicon thin-film resistor

Abstract

The invention relates to a method for improving the stability of a polysilicon thin-film resistor. The method comprises the following steps: (a) mounting false pieces at an interval inside an insertion slot of a polysilicon deposition boat, and performing polysilicon deposition on the false pieces for at least twice through ion implantation equipment; (b) mounting a substrate, and allowing growthof an oxide layer on the substrate; (c) performing polysilicon deposition on the substrate through the ion implantation equipment; (d) performing ion implantation to a polysilicon thin layer; (e) coating the polysilicon thin layer with photoresist; (f) etching the polysilicon thin layer; (g) performing drain ion implantation to the polysilicon thin layer; (h) removing the photoresist; (i) forminga metal front dielectric film on the polysilicon thin layer; (j) annealing the polysilicon thin layer on the substrate; (k) forming a contact hole on the metal front dielectric film; and (l) depositing metal material inside the contact hole to form a metal connecting wire. The method provided by the invention can improve the process capability of the polysilicon thin-film resistor, has the advantages of simple process operation and high safety and reliability, and reduces processing cost.

Description

technical field [0001] The invention relates to a method for improving the stability of polysilicon thin film resistance, specifically a method capable of improving the stability of the polysilicon thin film resistance process and the process capability of the polysilicon thin film resistance process, which belongs to the technical field of integrated circuits. Background technique [0002] Polysilicon thin film resistors are often used in CMOS and BiCMOS (bipolar complementary metal-oxide-semiconductor) integrated circuit processes. The polysilicon used in the MOS gate structure is heavily doped to improve conductivity. Usually, the sheet resistance is 25~ 50Ω / SQ (square). The lightly doped polycrystalline film is generally several hundred to several thousand ohms per square, and the conductivity of the polycrystalline silicon film resistor is not only related to the doping amount, but also related to the grain structure of the polycrystalline silicon film. The grain bound...

AI Technical Summary

Problems solved by technology

Due to the impact of the current ion implantation equipment that cooperates with the polysilicon deposition boat, it will reduce the stability of the polysilicon film on the silicon wafer. The poor stability of the polysilicon film resistance during the particle implantation process is mainly manifested in: there is a step change, the step is 10 pieces are distributed in a step; the uniformity within the slice is poor, showing a circular distribution with a small center and a large edge; the uniformity within a batch is poor, and the range is very large; the uniformity between batches is poor, and the variation between batches is large

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