TiN-Layer Formation by N Ion Implantation

Abstract

100keV N⁺₂ ions were implanted into deposited-Ti and bulk-Ti with the dose of 1X10¹⁷-1X10¹⁸ions/cm² at the temperature from R.T. to 1000°C. The surfaces were studied by Rutherford backscattering spectrometry(RBS), scanning electron microscopy(SEM), X-ray diffraction and Knoop-hardness measurement.
When implantation dose was 5X10¹⁷ions/cm², the formed layer had the chemical composition of Ti:N=1:1 and the thickness of 1000-2000Å. It was found that the appropriate temperature to form TiN layer is about 600°C. At the temperature below 400°C, blisters were formed and TiN crystals didn't grow up and the hardness didn't rise notably. At the temperature above 800°C, implanted nitrogen diffused quickly and lost, thereby TiN layer wasn't formed and the hardness didn't rise. It was also found that the formed TiN structure depends on the structure of Ti substrate.