The photoemission study of InSb/HfO2 stacks upon N2 rapid thermal annealing

Antimonide based III-V materials are widely used in quantum-well transistors and long wavelength optoelectronic devices benefit from their narrow bandgaps and high carrier mobilities. Interface chemistry has proven to be important in establishing reliable devices. The InSb/HfO2 stacks have been systematically studied upon atomic layer deposition (ALD) and rapid thermal annealing (RTA) at 325 °C and 400 °C, utilizing X-ray photoelectron spectroscopy (Al Kα1) and synchrotron radiation photoemission spectroscopy. No “clean up” effect was observed after the ALD process. The interface oxidization, elemental diffusion and substrate oxide desorption have been observed upon the RTA process. This work highlights the importance of substrate passivation prior to ALD process to obtain a thermally stable InSb/HfO2 interface for InSb based devices.