document: The most widely used ion source in FIB instruments is a gallium (Ga) liquid metal ion source (LMIS) [1]. Gallium is attractive as an ion source because of its low melting temperature (29.8°C at standard atmospheric pressure [4]) and its low volatility [1]. However, some materials show sensitivity to the Ga ion beam. This sensitivity is manifested as changes in the structure and chemical composition of the starting material upon exposure to the Ga ion beam [5]. Group III–V compound semiconductors are one class of materials that show such sensitivity. Cryo-FIB milling has recently been reported to suppress the reactions between the Ga ion beam and III–V materials [6]. The suggested advantage of cryo-FIB milling over room temperature milling of Group III–V materials is appealing, given the variety of present and potential future applications for these materials (e.g., as electronic or photonic devices given the favorable electron transport and direct band gap properties associated with several III–V semiconductor systems).
extractive_keyphrases: fib instruments ga gallium group iii–v materials iii–v materials semiconductor semiconductors
abstractive_keyphrases: cryo-fib milling electronic or photonic device ga ion beam