Auxiliary graph formation method and exposure target graph correction method

Abstract

The invention discloses an auxiliary graph formation method and an exposure target graph correction method, the auxiliary graph formation method is as follows: a lower layer graph and a current layer graph are overlapped to form a second graph; a third graph is obtained by negation of the second graph; size length and width of the third sub graph are shrunk to first preset values to form a fourth graph; and a non-exposable part fourth sub graph in the fourth graph can be removed to form a fifth graph, and the fifth graph is used as an auxiliary graph of the current layer graph. The exposure target graph formation method is as follows: a lower layer exposure target graph and a to-be-corrected graph are overlapped to form an overlapping graph; a photolithographic resolution limit table is established; according to the photolithographic resolution limit table, the size of first to-be-corrected sub graph part which is overlapped with a first lower layer sub graph is corrected to form a first corrected sub graph. The mask light transmittance can be improved, and n the exposure target graph correction accuracy can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for forming an auxiliary pattern and a method for correcting an exposure target pattern. Background technique [0002] With the continuous decline of semiconductor process nodes, the use of a mask as a mask to form a patterning process under the traditional lithography process has encountered limitations. The pitch of adjacent patterns is too small. Due to the optical proximity effect, adjacent patterns will appear. The phenomenon of sticking. [0003] Based on the fact that the critical dimensions of semiconductor devices are getting smaller and smaller, a double patterning (Double patterning) method is used to solve the above-mentioned problems. [0004] In the double patterning method, the pattern to be formed is divided into two kinds of patterns, namely the first mask pattern and the second mask pattern, and then the first patterning is performed to form the...

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Problems solved by technology

[0006] The second mask pattern is determined by the first mask pattern. The number of sub-patterns in the existing second mask pattern is small, resulting in poor light transmittance of the mask plate, which leads to photolithography in the second patterning. The size of the exposure patterns formed on the photoresist during the process is not uniform, which affects the accuracy of subsequent etching patterns

Considering the problem of etching deviation in the second patterning process, it is necessary to perform etching deviation compensation on the exposure target pattern, but since the compensation effect of the exposure target pattern is affected by the etching pattern of the underlying material, it is not consistent with the exposure target pattern. The size and pitch of the sub-patterns in the graphics are related to the size and spacing of the sub-patterns themselves, and also related to the graphics material and size in the etching pattern of the underlying material, so it is difficult to accurately compensate the etching deviation for the exposure target graphics

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