Cuイオンビームを照射した高純度アルミニウムの電解エッチング挙動

抄録

This paper, which clarifies effects of Cu ion beam irradiation with a tandem accelerator and an ion implanter on the morphologies of initial pits and on pit growth in high-purity aluminum, describes investigations of direct current (DC) etching and rectangular alternating current (AC) etching in hydrochloric acid solutions. Results of SIMS analysis confirmed that the Cu ion depths in specimens irradiated with the tandem accelerator and the ion implanter were approximately 1 μm at 1.5 MeV, 3 μm at 6 MeV (tandem accelerator), and 0.2 μm at 300 keV (ion implanter), respectively. These depths almost agreed with theoretical values. During DC etching, many facets were produced on the tips of tunnel pits through the zone of Cu ion concentration. The Cu ions in aluminum foils irradiated with the tandem accelerator cause excessive facet dissolution during tunnel pit growth. Plural facets on the cubic pits' side walls were observed in Cu ion irradiated specimens after AC etching. Results suggest that Cu ion irradiation of high-purity aluminum accelerated facet dissolution during the anodic half cycle of AC etching. Consequently, the excessive facet dissolution caused by Cu ions irradiated in aluminum is inferred to prevent pit propagation and extension of horizontal pit growth.