高周波支援マグネトロンスパッタリング法におけるAr^+及びTi^+のエネルギー分布のAr圧力依存性 Dependence of Ar^+ and Ti^+ Ion Energy Distributions on Ar Pressure in Inductively Coupled rf Plasma Enhanced Magnetron Sputtering
Effects of Ar pressure on the number of the <SUP>48</SUP>Ti<SUP>+</SUP> ions incident to the substrate have been investigated in inductively coupled rf plasma enhanced magnetron sputtering. The energy distributions of the <SUP>40</SUP>Ar<SUP>+</SUP> and <SUP>48</SUP>Ti<SUP>+</SUP> ions incident to the substrate were measured by an energy-resolved mass spectrometer. In addition to the energy distribution measurements, plasma conditions have been measured by a Langmuir probe technique to investigate the effects of Ar pressure on plasma. The experimental results of the ion energy distribution measurements show that the number of <SUP>48</SUP>Ti<SUP>+</SUP> ions arriving at the substrate increased as Ar partial pressure increased and that the number of <SUP>40</SUP>Ar<SUP>+</SUP> ions arriving at the substrate increased to an Ar pressure of 1.0 Pa and decreased for further increase in Ar pressure. From electron temperature measurement results, it was found that electron temperature decreased with increasing Ar pressure. The main process of Ti ionization is ascribed to the Penning effect, the ionization of Ti by the excited neutral Ar, resulting in a decrease of plasma temperature. It is concluded that an increase in Ar pressure enhances the ionization probability of Ti sputtered atoms.
真空 42(3), 413-416, 1999-03
The Vacuum Society of Japan