Novel bottom antireflective coating working for both KrF and ArF excimer laser lithography

Hexamethyldisiloxane (HMDSO) is used as coating material in a conventional ECR-PECVD process. By simply adjusting the gas flow rate ratio, the material can be varied to have suitable optical constants for making bottom antireflective coating (BARC) layers working at both 248 nm and 193 nm wavelengths. The measured reflectances lower than 1% on a silicon crystal substrate at both wavelengths have been achieved. The swing effect in the resist is significantly reduced. We also show that an HMDSO-based multi-layer structure can be used for broadband AR coating in deep ultraviolet regimes.