The mechanical property of TiN film deposited on N+-implanted aluminum by magnetron sputtering

The effect of a AIN gradient interlayer on the surface mechanical properties was investigated by nano-indentation for the TiN film on N+-implanted Al substrate. The AIN interlayer, 80mn thick measured by Auger Electron Spectrometer (AES), was formed by high energy W-implantation prior to magnetron sputtering the TiN film in our custom designed multifunctional ion implanter. The nanohardness of N+-implanted aluminum was 450HV at extremely small depth, but quickly decreased to a constant value (65HV). The hardness and Young's modulus of the TiN film on two different substrates, one with and the other without W-implantation, kept almost constant up to a small depth of 200nin, and then decreased to the values of the Al substrate with increasing indentation depth, but with a lower decreasing rate for the N+-implanted system. It was found from the load-displacement curves that the interfaces cracked when the indentation load was 38mN for the W-implanted system, while 18mN for the unimplanted system. Therefore the N+- implantation improved the surface mechanical properties significantly.