Resistance changes of SnO/sub 2/ thin films suitable for microelectronic gas sensors

A simple method for the separate estimation of the electrical sheet resistivity (/spl rho//sub s/) and the contact resistivity (/spl rho//sub c/) is developed. The influence of an oxygen annealing on /spl rho//sub s/ and /spl rho//sub c/ of thin SnO/sub 2/ layers with W/Al, Cr/Al and Ti/Al contacts is investigated as an illustration of the method. The method is applicable for evaluation of very high resistivity layers, because "potential" measurements are not needed.