Etching mask group and substrate etching method applying same

Abstract

The invention provides an etching mask group and a substrate etching method applying the same. The etching mask group comprises a first mask layer made of a photoresist material, and a second mask layer made of a material capable of improving an etching selectivity ratio relative to a substrate, wherein the first mask layer is arranged on the surface of the substrate, the second mask layer is arranged on the first mask layer; and the widths of the bottom portions of respective patterns of first mask layer and the second mask layer are arranged in such a way that the inclination angle of a preset connecting line between the first mask layer and the second mask layer is consistent with a fixed inclination angle of the first mask layer. The etching mask group provided by the invention can realize the purpose of improving the pattern morphology of the substrate.

Description

technical field [0001] The invention relates to the technical field of microelectronics, in particular to an etching mask set and a substrate etching method using the same. Background technique [0002] PSS (Patterned Sapp Substrates, patterned sapphire substrate) technology is currently a commonly used method to improve the light extraction efficiency of GaN (gallium nitride)-based LED devices. During the PSS process, it usually grows a mask for dry etching on the substrate, and uses a photolithography process to carve the mask into a pattern; then uses ICP technology to etch the surface of the substrate to form the required pattern , and then remove the mask, and use the epitaxial process to grow a GaN film on the etched substrate surface. At present, because the graphic morphology obtained by etching the substrate surface with ICP technology can affect the light extraction effect of LED devices, especially the conical graphic morphology with straight side walls can signi...

AI Technical Summary

Problems solved by technology

However, due to the poor etch resistance of the photoresist mask, its lateral shrinkage speed is too fast, resulting in a small inclination angle C of the sidewall top 2, that is, the corners on the substrate sidewall (sidewall bottom 1 and The included angle of the top 2 of the sidewall) is too large, so that the over-etching step cannot modify the sidewall straight, and the finally obtained graphic appearance is that the sidewall forms an arc shape that is insufficiently modified, such as figure 2 shown

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