Thermal Etching Characteristics of AgInSbTe Phase Change Film

The etching characteristics of the AgInSbTe phase change film as a new thermal lithography material were studied. The amorphous AgInSbTe film was deposited by using radio frequency magnetron sputtering method at room temperature, and then crystallized by vacuum-annealing. Using sodium hydroxide aqueous solution as etchant, influences of annealing temperature, etchant concentration and etching time on etching properties of the amorphous and crystalline AgInSbTe films were investigated. Experimental results indicate that the etching rate of the amorphous AgInSbTe film is lower than 0.04 nm/s in 0.001 mol/L sodium hydroxide solution. After vacuum-annealing, the etching rate of the film increases markedly and the etching selectivity between the crystalline and amorphous films increases with the increase of the annealing temperature. At the etching time of 20 min, the etching rate of the crystalline AgInSbTe film annealed at 300℃ is 45 times higher than that of the amorphous film. The surface quality of the AgInSbTe film after etching is good, and the surface roughness is less than 1nm in the area of 10 μm×10 μm. The wet-etching mechanism of the AgInSbTe film in sodium hydroxide solution is discussed.