Method for etching silicon carbide shallow trench

Abstract

The invention discloses a method for etching a silicon carbide shallow trench, which comprises the steps of coating a silicon carbide epitaxial layer with a photoresist; patterning the photoresist; performing dry etching on the silicon carbide epitaxial layer by taking the patterned photoresist as a mask, wherein the parameters of the dry etching include SF6 and O2 which are cyclically and alternately introduced; and removing the photoresist. According to the method provided by the embodiment of the invention for etching the silicon carbide shallow trench, the silicon carbide epitaxial layer is coated with the photoresist, and the etching is performed by directly taking the photoresist as a mask, so that the number of masks is reduced, the etching efficiency is improved, the etching difficulty is reduced, and the batch production cost of silicon carbide devices is effectively reduced. The gases SF6 and O2 are cyclically and alternately act on the material, so that the etching rate of the photoresist can be reduced on one hand, and the side wall angle of the silicon carbide trench is facilitated to be improved on the other hand.

Description

Technical field [0001] The invention relates to the field of semiconductor devices, in particular to a silicon carbide trench etching method. Background technique [0002] The electrical parameters of the third-generation semiconductor SiC material and the traditional semiconductor substrate material (Si) are very different. SiC material has large thermal conductivity, wide band gap, high electron saturation velocity and breakdown voltage, and low dielectric constant. These characteristics determine its use in high-temperature, high-frequency, and high-power semiconductor devices. The application potential of the current semiconductor field is gradually shifting to silicon carbide materials. Because the physical parameters of silicon carbide materials and silicon materials are quite different, it is impossible to apply the process preparation scheme of traditional silicon substrate materials. This patent proposes an etching process plan for silicon carbide materials. The main r...

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Problems solved by technology

[0004] It can be seen that the traditional silicon carbide trench etching method involves two etching steps. Since the two mask materials are different and the removal methods are also different, it is easy to cause process errors, introduce new impurities, etc. during the complicated preparation process. Faced with problems such as difficulty in removing the SiO2 mask, and the angle of etching the sidewall of the silicon carbide trench in the prior art is difficult to achieve satisfactory results

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