PRECURSOR FILM AND METHOD OF FORMING THE SAME

摘要

A precursor film having a required gallium component proportion is formed easily at low cost. A precursor film for use in forming the light absorption layer of a CIS type thin-film solar cell, etc., or a method for forming the film are provided. A Cu-Ga layer having a high gallium component proportion (Ga/ (Ga+Cu)) of X% by weight Ga is formed as a first layer by sputtering using a precursor film comprising a Cu-Ga alloy layer having the gallium component proportion of X% by weight Ga as a target (deposition step A). Thereafter, a copper layer is formed as a second layer on the first layer by sputtering using a copper layer as a target (deposition step B) to thereby form a precursor film having the required gallium component proportion of Y% (X>Y) by weight Ga as the sum of the first layer and second layer. A method of film formation by simultaneous vapor deposition is also possible.