Etching thin tin di:oxide and/or indium oxide layers - by reduction with hydrogen generated by zinc and hydrogen chloride

摘要

In the parent patent thin SnO2 layers are etched by contact with Zn and an aq. HCl soln. in an etching appts. In a 1st appts. zone, the aq. Zn powder paste-covered substrate is wetted with a measured out HCl supply so that H2 generation and SnO2 reduction are uniform over the whole substrate surface. In a 2nd zone, the residual Zn powder is removed immediately from substrate surface with an ample HCl supply, redn. is stopped and the redn. prod. is dissolved in HCl. In this addn. this process is used for etching In2O3- and SnO2-In2O3 mixt. layers. H2 generated reduces SnO2 to Sn and In2O3 to In, or a mixt. of these oxides to Sn and In.