Gettering effects of helium cavities created by high dose plasma immersion ion implantation

Summary form only given, as follows. Helium bubbles are formed in silicon using high dose plasma immersion ion implantation (PIII). Thermal annealing of the implanted sample at temperature over 700/spl deg/C causes the helium bubbles to diffuse out of the silicon substrate. The cavities formed provide active sites for impurity gettering. The gettering of copper and gold impurities are characterized by secondary ion mass spectrometry and the results demonstrate that the cavities are effective sinks for copper and gold. The gettering process also remains stable up to 1200/spl deg/C. PIII is thus an excellent technique to create cavities for gettering sites, for example, on the backside of silicon wafers. The high-dose and immersion characteristics of PIII make it an ideal technique for future 300 mm and 400 mm silicon wafers.