Pattern interactions of post exposure bake in litho-cure-litho-etch process
Semiconductor manufacturing depends on optical lithography. The most basic parameters of the photolithography technique are the resolution and the cost. As the wavelength becomes shorter, the light source and optics become more complex and expensive. The litho-cure-litho-etch (LCLE) process, which is composed of two lithography processes (litho 1 and litho 2) and an intermediate curing step, can reduce the number of process steps and the cost compared to the litho-etch-lithoetch (LELE) process. In this research, the post-exposure bake (PEB) of the LCLE process was investigated. Advanced modeling techniques for the PEB process and the curing process are introduced to explore pattern interactions between the two lithography processes in the LCLE process. Using the simulation results, we discuss the impacts of the depletion of the acid concentration in the vicinity of cured patterns and of acid/quencher diffusion effects on the pattern formation of the LCLE process.
KeywordsLithography Lithography simulation Double patterning Litho-cure-litho-etch Litho-freezelithoetch Litho-etch-litho-etch
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