UV laser deposition of thin films at 248 NM for phase shifting mask repair

Laser-induced deposition of controlled quality silicon dioxide and thin metallic films was investigated at 248 nm for phase shifting mask (PSM) repair. SiOx (x=1.5-2) films were deposited from single precursors, such as triethoxyvinylsilane (TEVS), tetraallyloxysilane (TAOS), di-t-butoxy-diacetooxysilane (TBSA) with no oxidizing coreactant. A deposition rate of 0.25 angstrom/pulse was possible at room temperature, with excellent optical properties (n=1.47, k=0.05). Metallic films were deposited from tungsten, gold, molybdenum and chromium compounds. The results showed that the optical transmission and phase-shifting properties of the deposits can be matched well to the films commonly used in phase shifting masks.