Method of etching copper indium gallium selenide (CIGS) material

Methods for dry plasma etching thin layers of material including Cu(In, Ga)Se, e.g., CIGS material on semiconductor substrates are provided. A method of etching a CIGS material layer such as copper indium gallium selenide film, includes: flowing an etching gas including a mixture of gases into a process chamber having a substrate disposed therein, the substrate including a copper indium gallium selenide layer having a patterned film stack disposed thereon, the patterned film stack covering a first portion of the copper indium gallium selenide layer and exposing a second portion of the copper indium gallium selenide layer; and contacting the copper indium gallium selenide layer with the etching gas to remove the second portion and form one or more copper indium gallium selenide edges of the first portion.