High K insulators, such as aluminum oxynitride (AlNxOy), have been obtained by DC sputtering deposition, using different deposition times of 5s, 20s, 30s, 60s and 90s, in a nitrogen/argon ambient with additional rapid thermal oxidation and annealing at the temperature of 9600C for 40s. Characterization by Fourier Transform Infrared (FTIR) and secondary ion mass spectroscopy (SIMS) analysis reveal the Al-N, Al-N-O, Si-O, Al-O bonds, confirming aluminum oxynitride film formation. These films have been used as gate insulators in the enhancement pMOSFETs. These devices and MOS capacitors, with Al electrodes and final sintering time for 10 min at 4500C in forming gas flux, were fabricated. MOS capacitors were used to obtain capacitance-voltage (C-V) measurements. A relative dielectric constant of 3.9 was adopted to extract the equivalent oxide thickness of films from C-V curves under strong accumulation conditions, resulting in values between 6.6 nm and 17 nm, and the effective charge densities of about 1011 cm-2. pMOSFET electrical characteristics, such as threshold voltages between 0.9V and 1.1V, transconductances between 78 µS and 144 µS, and sub-threshold slopes between 65 mV/dec and 91 mV/dec, were obtained. These results indicate that the obtained AlNxOy films are suitable gate insulators for metal-oxide-semiconductor (MOS) devices.
Keywords: aluminum oxynitride, high K dielectrics and sputtering deposition
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