Method for making shallow groove insolation structure

Abstract

The present invention discloses a method for making a shallow groove insolation structure. The method comprises the steps: a padding oxide layer is formed on a substrate; a cease layer is formed on the padding oxide layer; a shallow groove insolation structure pattern is formed on the cease layer; the cease layer and the padding oxide layer are previously etched by taking the shallow groove insolation structure pattern as a covering film to form a groove opening; arc processing is carried out for the groove opening in at least two steps, and polymers produced from used gas in all steps are orderly reduced; the groove opening after arc processing is primarily etched to form a groove; the groove is filled; and a shallow groove insolation structure is formed after flattening processing. The adoption of the method for making a shallow groove insolation structure can ensure that the side walls on the top of the groove in the junction of a dielectric layer and the silicon substrate are smooth. The electrical properties of devices, such as current leakage, etc are effectively improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for forming a shallow trench isolation structure. Background technique [0002] The integrated circuit manufacturing process is a planar manufacturing process that combines photolithography, etching, deposition, ion implantation and other processes to form a large number of various types of complex devices on the same substrate and connect them to each other to have a complete electronic functions. Among them, any deviation in the process may cause the performance parameters of the circuit to deviate from the design value. At present, with the continuous proportional reduction of the device feature size of VLSI and the continuous improvement of integration level, higher requirements are put forward for the control of each step of the process and the accuracy of the process results. [0003] Take the shallow trench isolation structure formed in the s...

AI Technical Summary

Problems solved by technology

[0012] figure 2 For trench patterns formed using existing shallow trench isolation structure formation methods, such as figure 2 As shown in the middle circle 201, the sidewall of the formed trench is not smooth, and a depression appears on the top sidewall (the junction of the pad oxide layer and the silicon substrate), which will increase the leakage current of the device and be detrimental to the electrical performance of the device.

[0013] The Chinese patent application with publication number CN101162692A published on April 16, 2008 describes in detail a method for etching a silicon wafer, and specifically adjusts the etching process of the trench to form a circular groove at the top and bottom. Corner groove structure, but judging from its effect diagram, the shape of the groove formed by it is poor, and it is not suitable for small-sized devices with high requirements on shape and size.

Images