Titanium ion implantation into silicon substrate by plasma-based metal ion implantation system with 100-kV/2.5-A pulse modulator

摘要

A pulsed, metal-ion implantation system with a pulse modulator with specifications of 100 kV/2.5A/30 mu s has been developed. Titanium ions were implanted into a silicon substrate (n-n(+), [111], 400 mu m in thickness) using applied voltages of 20-50 kV with a negative polarity and repetition rates of 180-1800 Hz for d.c. are current of 60 A. Neither the implantation profile nor the depth is affected by changes in the repetition rate. As the applied voltage increases, both the total dose and the ion range increase. The dose can be achieved up to the order of 10(17) atoms cm(-2). The dose is proportional to the repetition rate and linearly related to the applied voltage. Changes in the characteristics in RES spectra from implanted samples are observed as a result of varying the applied voltage. These changes suggest the existence of the mixing layer of titanium and silicon including a silicide structure. By adjusting the applied voltage and repetition rate, the degree of the mixing of titanium and silicon can be controlled to create new material compositions. (C) 1998 Elsevier Science S.A. [References: 10]