Method for increasing two-dimensional pattern resolution

Abstract

The invention discloses a method for increasing the two-dimensional pattern resolution, which comprises the following steps of: adding a split type serif on the basis of the originally designed two-dimensional angle photomask pattern, wherein the serif is added around the two-dimensional angle photomask pattern; and then, carrying out photoetching according to the main design pattern and the serif pattern to obtain a two-dimensional angle photoetching pattern with high resolution. In the invention, OPC (Optical Proximity Correction) is carried out on the two-dimensional angle pattern by adopting the split type serif, both the simulated pattern and the pattern after the actual chip photoetching can be obviously improved through being compared with the traditional serif simulated and photoetched patterns, the pattern is more similar to the designed pattern, the design requirements of the invention are also met, and the invention can be used in processes with higher conformal requirementon the two-dimensional angle pattern such as SiGe BCD, and the like.

Description

technical field [0001] The invention relates to an optical proximity correction method in the manufacture of integrated circuits, in particular to a method for increasing the resolution of two-dimensional graphics. Background technique [0002] In the advanced photolithography process, due to the reduction in the size of the exposure pattern, optical proximity correction (Optical Proximity Correction, OPC) must be performed on the photomask pattern in advance to compensate for the optical proximity effect caused by the limited resolution of the optical system. In the traditional rule-based optical proximity correction, the method of adding a supplementary block (serif) to the two-dimensional corner figure is used to increase the resolution of the figure (see figure 2 ) to make it as consistent as possible with the design graphics. However, due to the limitation of the resolution of the lithography process, the traditional serif pattern cannot meet some process requirements ...

AI Technical Summary

Problems solved by technology

However, due to the limitation of the resolution of the lithography process, the traditional serif pattern cannot meet some process requirements that require high conformality of the two-dimensional corner pattern (see Figure 4 , 6), such as SiGe BCD (SiGe Bipolar-CMOS-DMOS, silicon germanium bipolar complementary MOS-double diffused MOS) process, the rectangular hole in the emitter window process requires as much square as possible in the corner to approach the layout design ( See figure 1 )

[0003] Generally, the process that requires high conformality of two-dimensional corner patterns will use the method of reducing the exposure wavelength of lithography. For example, if the exposure machine with a wavelength of 248nm is replaced with an exposure machine with a wavelength of 193nm, the shape retention of two-dimensional corner patterns will be improved. increase, but the production cost has increased a lot

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