Splicing and exposure method of sapphire substrate

Abstract

The invention provides a splicing and exposure method of a sapphire substrate. The splicing and exposure method comprises the following steps: preparing a mask pattern on a mask according to a pattern to be prepared on the surface of the sapphire substrate before exposure, wherein the mask pattern comprises a light transmitting area and a light-proof area, the light-proof area is composed of a plurality of unit patterns distributed on the light-proof area regularly; exposing all exposure areas of the surface of the sapphire substrate by the mask during exposure, and splicing exposure patterns of two adjacent exposure areas; arranging a light transmitting redundancy part outwards on the boundary part of the mask pattern for enhancing the exposure energy at the splicing position of two adjacent exposure areas. According to the splicing and exposure method of the sapphire substrate, energy of the spliced position can reach the threshold energy due to the design of the redundancy part, and residual gum can be eliminated; and as the exposure energy of the spliced position is consistent to that of other positions, the change of critical dimension (CD) can be avoided.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a splicing exposure method for a patterned sapphire substrate. Background technique [0002] Patterned sapphire substrate (Patterned Sapphire Substrate, PSS), that is, a mask for dry etching is grown on the sapphire substrate, and the mask is patterned with a standard photolithography process, and the sapphire is etched using ICP etching technology , and remove the mask, and then grow GaN material on it, so that the vertical epitaxy of GaN material becomes lateral epitaxy. On the one hand, it can effectively reduce the dislocation density of the GaN epitaxial material, thereby reducing the non-radiative recombination of the active area, reducing the reverse leakage current, and improving the life of the LED; on the other hand, the light emitted by the active area passes through GaN and sapphire Multiple scattering at the interface of the substrate changes the exit angl...

AI Technical Summary

Problems solved by technology

In this case, for example, if the reduction ratio is 5:1, in order to ensure the exposure, it is necessary to actually use a mask that is 5 times the exposure field for exposure, which increases the difficulty of the operation and consumes too much cost

[0005] In addition, when making patterned sapphire substrate (PSS) by stepping exposure method, due to factors such as workpiece table servo performance, aberration and lens resolution, the CD at the splicing part of the exposure field will be significantly affected

Especially when half of the distance between the two patterns is close to or smaller than the minimum resolution of the lithography machine, it will cause CD changes or residual glue at the splicing point, which will affect the uniformity of the final PSS pattern

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