Plasma etching method of insulating layer containing silicon

Abstract

The invention discloses a plasma etching method of an insulating layer containing silicon, comprising an etching step and a side wall passivation step which are mutually independent, wherein the etching step and the wall passivation step are alternated and recycled in the etching process until the target depth is obtained by etching. The etching step comprises: etching gas is provided to etch an insulating material layer containing silicon under the action of plasma to a certain depth so as to expose one etching interface, wherein the etching interface comprises a side wall; and the side wall passivation step comprises: reaction gas containing carbon and hydrogen is provided, polymer containing carbon and hydrogen is formed on the side wall of the etching interface under the action of plasma and is deposited or attached to the side wall surface of the etching interface. The etching method of the invention quickly etches the insulating layer containing silicon and protects the side wall, obtains better appearance outline and solves the problems that the arc-shaped side wall and critical dimension when channels or through holes are etched in the prior art are offset.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor devices, in particular to a plasma etching method for an insulating layer containing silicon. Background technique [0002] The etching process refers to the process of removing unnecessary parts in the wafer or in the film layer on the surface of the wafer by using chemical solution or corrosive gas or plasma in the process of manufacturing semiconductor devices. Generally, the etching method mainly using chemical solution is wet etching, and the etching method using corrosive gas or plasma is dry etching. At present, dry etching, which can make circuit patterns finer, is more and more widely used. [0003] In wet etching, the chemical reaction of strong acid is used for isotropic etching, 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, and p...

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Problems solved by technology

[0006] Simultaneous supply of etching gas and sidewall protection gas can achieve anisotropic etching (anisotropic etch), but it will have a great impact on the etching rate, resulting in a decrease in etching rate, and due to the etching gas, sidewall The shielding gas, the etching target layer and even the mask layer on the target layer are all involved in the entire reaction process. The entire reaction process is affected by many factors, and different factors interact, so it is difficult to debug and obtain the best etching parameter configuration. , even if it is obtained, it will take a lot of manpower and time

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