Nanocavities: an Effective Gettering Method for Silicon-on-Insulator Wafers
ZHANG Miao1, ZENG Jian-min1, HUANG Ji-po1, LIN Zi-xin2, ZHOU Zu-yao2, LIN Cheng-lu1
1State Key Laboratory of Functional Materials for Informatics, 2Ion Beam Laboratory, Shanghai Institute of Metallurgy, Chinese Academy of Sciences, Shanghai 200050
Nanocavities: an Effective Gettering Method for Silicon-on-Insulator Wafers
1State Key Laboratory of Functional Materials for Informatics, 2Ion Beam Laboratory, Shanghai Institute of Metallurgy, Chinese Academy of Sciences, Shanghai 200050
Abstract： The 4×1016 /cm2 H+ and 9×1016/cm2 He+ have been implanted into the silicon substrate of separation-by-implantation-of oxygen (SIMOX) wafers, respectively, followed by a 700°C annealing to form nanocavities beneath the buried oxide (BOX) layer. The SIMOX wafers were intentionally contaminated with Cu impurities by implanting different doses of Cu in the top Si layer. Secondary ion mass spectroscopy and cross-sectional transmission electron microscopy technologies have been employed to investigate the gettering effect of nanocavities to the Cu impurities. The cavities induced either by H+ or He+ implantation are effective gettering centers for Cu in SIMOX wafers. After annealing at 1000°C for 90 min, up to 4 ×1015 /cm2 Cu has diffused through the BOX layer and been captured by the cavities. The gettering efficiency of cavities increases with the decrease of Cu implantation doses. The nanocavities provide an attractive method for gettering transition metal impurities in SIMOX materials.
1998, Vol. 15 
