Depth resolution degradation of sputter-profiled InP/In/sub x/Ga/sub 1-x/As/sub y/P/sub 1-y/ interfaces caused by cone formation

Both InP and In/sub x/Ga/sub 1-x/As/sub y/P/sub 1-y/ surfaces with trace metal contaminations are unstable with respect to cone formation when sputter etched by Ar+. Such gross surface texture severely degrades the depth resolution of sputter profiling techniques. Cone formation can be prevented by avoiding contamination of the material being profiled with metals sputtered from various surfaces in the analysis system. An uncorrected width of 140 A was determined using techniques which optimize sputter depth profiling for an In/sub 0.74/Ga/sub 0.26/As/sub 0.60/P/sub 0.40/-InP heterojunction grown by liquid phase epitaxy