Chemical vapor deposition of tin oxide films

A new technique is described for the deposition of SnO2films based upon the pyrolysis of tetramethyltin (TMT) in oxygen at relatively low temperatures ( c). As a 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 (1) high and controllable growth rates (more than 300 Å/min), (2) high conductivity layers (more than 30 Ω cm^-1undoped), and (3) highly transparent layers in the visible range more than 95% transmission for 1500 Å layers). In addition, the films can be doped to achieve conductivities as high as 200 cm^-1without loss in transmission. Finally, fast, effective low temperature anneals with forming gas in an open tube system can be used to result in a two-fold increase in conductivity.