Polarity influence on the indentation punching of thin {111} GaAs foils at elevated temperatures

Thin {111} GaAs substrates were deformed by a Vickers indenter at 350°C–370°C under loads ranging between 0.4 and 1.9 N. Optical microscopy and interferometry were used to observe the indented and opposite faces of the thin foils and hence to investigate the plastic flow through the samples. Attention was paid to the polarity (A or B) of the specimen surface, as GaAs is known to show a large difference between α and β dislocations mobilities. A model considering the influence of polarity is proposed to describe the material flow throughout thin samples.