Indentation fracture toughness of semiconducting gallium arsenide at elevated temperatures

Abstract

In this study, the temperature evolution of the fracture toughness in single-crystal gallium arsenide (GaAs) was investigated on the (001) plane using Vickers indentation. The highest temperature considered was 95 °C, corresponding to the typical maximum operating temperature of common GaAs semiconductor devices. Experimental results showed a decrease in hardness and an increase in toughness between 25 and 95 °C. GaAs cleavage planes were mostly composed of {110} and {100}, and predominantly aligned with the indenter’s diagonal. Measured crack lengths were used to calculate the fracture toughness. Interestingly, the size of the primary cracks on {110} was found to be unaffected by temperature, while higher temperatures led to an increased formation of secondary {001} cracks and 〈110〉 slip. An Arrhenius-type model was found to describe the observed temperature dependence of the fracture toughness. This improved understanding of the mechanism underlying the mechanical properties of GaAs during fracture is particularly useful for the failure analysis of GaAs semiconductor devices, and highlights the importance of selecting appropriate crystallographic orientations if failure in GaAs devices is to be avoided.