Chemical Vapor Deposition of Anti-Reflective Layer Film for Excimer Laser Lithography

Abstract

We report a new anti-reflective layer (ARL) film for KrF excimer lasers, which makes excimer laser lithography applicable to mass production of devices with a design rule tighter than 0.35 µm. The ARL film, which is composed of SiO x N y :H, was deposited with a higher SiH 4 /N 2 O ratio than in conventional PECVD (Plasma Enhanced Chemical Vapor Deposition) conditions. The SiO x N y :H films, with optimal refractive indices, were easily deposited by varying the SiH 4 /N 2 O ratio as a PECVD parameter. Using the SiO x N y :H film to fabricate a 16MSRAM gate structure, variations in photoresist absorption were significantly reduced.