| 摘要 |
Changing (varying, irregular) resist thickness on semiconductor wafers having irregular top surface topography or having different island sizes, affects the percent reflectance (and absorption efficiency) of incident photolithographic light, and consequently the critical dimensions of underlying features being formed (e.g., polysilicon gates). A low solvent content resist solution that can be applied as an aerosol provides a more uniform thickness resist film, eliminating or diminishing photoresist thickness variations. A top antireflective coating (TAR) also aids in uniformizing reflectance, despite resist thickness variations. The two techniques can be used alone, or together. Hence, better control over underlying gate size can be effected, without differential biasing.
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