Etching method and device for improving side wall streaks

Abstract

The invention provides an etching method and device for improving side wall streaks. The method is applied to a substrate, wherein a bottom anti-reflection layer and a hard mask layer are formed on the surface of the substrate. The method includes the following steps that the bottom anti-reflection layer is etched at the frequency of define source power, and at the time, cavity pressure is lower than 50 millitorrs; the hard mask layer is etched at the frequency of bias power, and at the time, the cavity pressure ranges from 300 millitorrs to 700 millitorrs; the define source power ranges from 25 MHz to 120 MHz, and the bias power ranges from 1 MHz to 15 MHz. When a bottom dielectric isolation layer is etched by means of the etching method and device for improving the side wall streaks, the rough streaks of the side faces of photoresists do not extend downward, so that damage to the surface and the side wall of a polymer layer is avoided. Compared with the prior art, by means of the method and device, the surface and the side wall of the etched polymer layer are not rough and do not have the streaks, and the streaks of through holes are greatly improved.

Description

technical field [0001] The invention relates to an etching process and a device for improving sidewall streaks, in particular to an etching process and a device for respectively etching a bottom anti-reflection layer and a hard mask layer through two different etching processes. Background technique [0002] Dry etching is a technique that uses plasma to etch thin films. When the gas exists in the form of plasma, it has two characteristics: on the one hand, the chemical activity of these gases in the plasma is much stronger than that under normal conditions. React with the material to achieve the purpose of etching and removal; on the other hand, the electric field can also be used to guide and accelerate the plasma, so that it has a certain energy. When it bombards the surface of the etched object, it will be etched The atoms of the object material are knocked out, so as to achieve the purpose of etching by physical energy transfer. Therefore, dry etching is the result of...

AI Technical Summary

Problems solved by technology

However, we found that even if only 60MHz is used to etch BARC and TEOS (or DARC), the DC bias generated by it is also very high, and the surface and sidewall of the photoresist are seriously damaged during the etching process.

Moreover, at around 60MHz, the concentration of the plasma is high, and the polymer produced is also heavy, which is difficult to control, and the uneven deposition of the polymer also causes serious sidewall streaks.

Images