The Preparation and Properties of Tin Oxide Films Formed by Oxidation of Tetramethyltin

A new technique is described for the deposition of films based upon the pyrolysis of tetramethyltin (TMT) in oxygen at relatively low temperatures (≈450°C). As a tin source, TMT has the advantages of being stable in air and moisture and of being a liquid with a relatively high vapor pressure at room temperature. Thus, a simple bubbler system is used to transport its vapors to the reaction chamber. The deposition technique is characterized by ( i ) high and controllable growth rates (more than 300 Å/min), ( ii ) high conductivity layers [more than 30 (ohm‐cm) −1 undoped], and ( iii ) highly transparent layers in the visible range (more than 95% transmission for 1500Å layers). In addition, the films can be doped to achieve conductivities as high as 200 (ohm‐cm) −1 without loss in transmission. Finally, fast, low temperature anneals with forming gas in an open‐tube system can be effectively used to result in an additional twofold increase in conductivity.