Gold coated YBCO films for room temperature FET-sensors

The thin films of high T-c cuprates are sensitive to gases at room temperat ure and are highly suitable for development of silicon based FET-sensors. H owever, an appropriate passivation is needed for their incorporation in sil icon-CMOS technology. Utilization of thin gold films for this purpose is re ported here for the gas sensing properties of gold-coated YBCO films. RF ma gnetron sputtering is used to deposit YBCO films on oxidized silicon substr ates. These films are then coated with a thin gold layer and used to constr uct discrete structures of capacitively controlled field effect transistor (CCFET) sensors to investigate their gas detection properties. The measurem ent technique and sensor response are discussed in detail. The results evin ce that gold-coated YBCO films are sensitive to ammonia at room temperature and can be employed as sensitive layer in integrated silicon-FET sensors f or detection of ammonia.