PRECURSOR FILM AND METHOD OF FORMING THE SAME

摘要

It is intended to form a precursor film of demanded Ga component ratio easily at low cost. There are provided a precursor film for use as a light absorption layer of CIS type thin-film solar cell, etc. and a method of forming the same. Using as a target a precursor film of Cu-Ga alloy layer of X wt.% Ga wherein the Ga component ratio (Ga/(Ga+Cu))is high, sputtering is performed to thereby form as a first layer a Cu-Ga layer of X wt.% Ga (film forming step A). Thereafter, using a Cu layer as a target, sputtering is performed to thereby form as a second layer a Cu layer on the first layer (film forming step B). By virtue of the sum of the first layer and the second layer, there can be realized a precursor film of, as demanded Ga component ratio, Y(X>Y) wt.% Ga. Also, there can be employed a film forming method according to simultaneous vapor deposition technique.