Controlled‐ambient photolithography of polysilane resists at 193 nm

Various polysilanes have been examined as self‐developed photoresists at 193 nm and the benefits of imaging these materials in controlled, reactive ambients have been determined. Plasticization of the irradiated polymer due to reaction with oxygen is avoided when dry, oxygen‐free ambients are employed. In addition, the redeposition of silicon from the ablated polysilane, which is prevalent in a one‐pulse imaging mode, is greatly reduced when NF3 or CF2Cl2 are used as exposure ambients. Laser desorption mass spectrometry indicates that thermally activated decomposition of the polysilanes at fluences >100 mJ/cm2 causes more extensive fragmentation of the desorbed molecules. This results in the formation of higher volatility products upon halogenation.