DIRECT WRITING IN POLYMETHYL METHACRYLATE FILMS USING NEAR-ULTRAVIOLET LIGHT OF AR+ LASER

Direct laser writing of micron-wide grooves in polymethyl methacrylate (PMMA) films with the scan speed of up to 100-mu-m/s is demonstrated using cw near ultraviolet radiation at 351 and 363 nm. For the PMMA film on a silicon substrate we have found that the light energy required for complete ablation increases with the decreasing of incident beam power and extremely rises up when the power becomes less than 10 mW. It is shown that the groove profile depends on the process parameters and nearly vertical resist walls can be obtained.