Study of HF defects in thin, bonded silicon-on-insulator dependent on original wafers

To study the origin of HF defects in thin, bonded silicon-on-insulator (SOI ) wafers fabricated by the plasma assisted chemical etching (PACE) process, the dependence of HF defects on original wafers [wafers fabricated by Czoc hralski method (CZ wafers), hydrogen-annealed CZ wafers and epitaxial wafer s] was investigated. It was shown that HF defect density was affected by th e type of original wafer used, and no HF defect was detected when epitaxial wafers were used as bond wafers. HF defects : were detected on 0.2 pm or t hinner SOI wafers with CZ wafers. Crystal originated particles (COPs) at SO I and buried bride (SOI/BOX) interface were found td be the main origin of HF defects by inspecting light point defects (LPDs) at the SOI/BOX interfac e.