Selective Wet Etching Characteristics of Aginsbte Phase Change Film with Ammonium Sulfide Solution

Abstract

The selective wet etching characteristics of AgInSbTe film as a new thermal lithography material were studied with ammonium sulfide solution as etchant. Influences of vacuum-annealing temperature, etchant concentration and wet etching time on selective wet etching characteristics of the amorphous and crystalline AgInSbTe films were investigated. Experimental results indicated that the etching rate of AgInSbTe film increased with the enhancement of crystallization extent, and the etching rate of crystalline state AgInSbTe film annealed at 300°C was 35nm/min in 17wt% ammonium sulfide solution, about 17.5 times as high as that of the amorphous state. Moreover, a good surface morphology of AgInSbTe film with roughness of less than 3 nm was attained in the area of 10×10 μm2 after wet-etching. The wet etching selectivity of the AgInSbTe film was strongly influenced by the annealing temperature and the etchant concentration.