| 摘要 |
PURPOSE:To execute good lithography by using an SiO2 film as a pellicle for preventing dust in an exposing system using excimer laser light (175 to 300nm wavelength). CONSTITUTION:The SiO2 film as the pellicle has adequately 1 to 5mum film thickness in terms of strength and light transmittance. For example, the SiO2 films are formed on both surfaces of an Si single crystal substrate by passing SiH4 and N2O on the Si substrate and subjecting the same to a plasma treatment. The SiO2 on the rear surface is partly subjected to dry etching by CF4/O2, etc., and thereafter, the substrate is immersed into a soln. mixture composed of HNO3, HF, and NaNO2 to selectively etch the Si substrate, by which the self-standing SiO2 film on the front surface is easily stably formed. The resulted thin SiO2 film has high UV transmittance and allows the good transmission of the excimer laser light having 175 to 300nm. |
