Patent ID: 8652870
Filing Date: 2014-02-18
Classification: H01L,Y02E,Y02P

Abstract:
1. A method for selenizing a Cu—In—Ga precursor film at high temperatures comprising: forming the Cu—In—Ga precursor film on a substrate; heating the substrate to a first temperature between about 350° C. and about 450° C. in an atmosphere comprising a Se-containing gas for a first period of time sufficient to partially selenize the precursor film; thereafter heating the substrate to a second temperature between about 550° C. and about 650° C. in an atmosphere comprising a Se-containing gas for a second period of time sufficient to further selenize the precursor film; thereafter removing the Se-containing gas from the heating atmosphere; and continuing the heating the substrate at the second temperature for a third period of time sufficient to allow Ga migration in the selenized film to influence the Ga distribution through the depth of the film; wherein the Se-containing gas is H wherein the Cu concentration in the Cu—In—Ga precursor film is between about 0.8 and 1.0 and is calculated as (Cu/(In+Ga)); wherein the removing the Se-containing gas prevents formation of a thick MoSe wherein the partial selenization of the precursor film secures the In in a selenized state and prevents agglomeration of In.