Method for etching plasma

Abstract

The invention relates to a plasma etching method. Before the step of etching a plurality of etching target layers on a semiconductor substrate, the invention comprises the step of ionizing the pretreatment gas containing the inert gas to form a pretreatment plasma and also comprises the step of treating the photoresist layer through the pretreatment plasma so as to avoid grooves being formed on the graphic sidewall of the photoresist layer, so that the shape etched on the dielectric layer is more in line with the expectation.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor devices, in particular to a plasma etching method. Background technique [0002] Etching is a process in which chemical solutions or gases are used to remove unnecessary parts from semiconductor wafers in the semiconductor device manufacturing process. Wet etching is usually mainly used for chemical etching, and dry etching, which can make circuit patterns finer, is more and more widely used. Dry etching uses corrosive gases or plasmas instead of chemical solutions. [0003] In wet etching, isotropic etching is performed with a strong acid chemical reaction, and even the part covered by the mask can be etched. In contrast, dry etching uses reactive ion etching, in which etching is performed with a corrosive chemical gas such as a halogen in a plasma state and ions in a plasma state. Therefore, dry etching can realize anisotropic etching that only etches in the vertical direction on th...

AI Technical Summary

Problems solved by technology

[0007] However, the above-mentioned method in the prior art has deficiencies. Since the target layer to be etched is usually thicker, the photoresist layer is correspondingly thicker, so high-energy plasma must be used to ensure the effect of the above-mentioned pretreatment Perform high-intensity pretreatment, but the high-energy plasma will also cause sputtering of the photoresist layer, destroying the photoresist layer

[0008] With the continuous reduction of feature size in semiconductor manufacturing, the above-mentioned plasma photoresist processing method still cannot meet the demand for maintaining a good etched shape, so it needs to be improved.

Images