Gate quality of ex situ deposited Al/SiNx : H/n-In0.53Ga0.47As devices after rapid thermal annealing

Abstract

Ex situ deposited SiNx:H/In0.53Ga0.47As metal-insulator-semiconductor devices, with a minimum of interface state density of 3.5 x 10(11) eV(-1) cm(-2) have been obtained by electron cyclotron resonance plasma method at a low substrate temperature (200 degrees C), after a rapid thermal annealing treatment. The effects of annealing temperature on interfacial and bull; electrical properties have been analysed using the C-V high-low frequency method and I-V measurements. The results show that, up to 600 degrees C, the annealing procedure gradually improves the interface properties of the devices. The frequency dispersion, the hysteresis and the interface trap density diminish, while the resistivity and the electrical breakdown field of the insulator film increase up to values of 8 x 10(15)Omega cm and 4 MV cm(-1), respectively. We explain this behaviour in terms of the thermal relaxation and the reconstruction of the SiNx:H lattice and its interface with the In0.53Ga0.47As. At higher annealing temperatures, a sharp degradation of the structure occurs.