CORRELATION OF IMPLANTATION DEFECTS WITH INTERFACE RECOMBINATION VELOCITIES AND CARRIER LIFETIMES IN ANNEALED SIMOX SOI MATERIALS BY USING A CONTACTLESS OPTICAL MODULATION TECHNIQUE

A contactless dual-beam optical modulation-(DBOM) technique [Y. S. Cha ng and S. S. Li, Solid-State Electron., 1995, 38, 297-304, Y. S. Chang , S. S. Li and P. C. Yang, Solid-State Electron., 1995, 38, 1359-1366] was employed to determine the interface recombination velocities and substrate carrier lifetimes in the SIMOX SOI wafers processed under di fferent implant energies (155-185 keV), temperatures (540-640 degrees C), beam currents (45-65 mA), and with channeling and non-channeling i mplants. The results revealed that using an implant energy of 185 keV, implant temperature of 640 degrees C, beam current of 45 mA, and with channeling implant yielded a better front-interface (Si film/buried o xide layer (BOX) interface) quality. In contrast, when an implant ener gy of 155 keV, a beam current of 65 mA, and non-channeling implant wer e used, a better back interface (BOX/Si substrate interface) was obtai ned. Similar to the back interface recombination velocity study, the D BOM measurements also showed that using an implant energy of 155 keV, implant temperature of 540 degrees C, beam current of 45 mA, and with non-channeling implant yielded a higher substrate carrier lifetimes. A n etch-pit method was used to correlate the Si-overlayer defect densit y with the front-interface recombination velocity determined by the DB OM technique. Good correlation was obtained between the measured inter face recombination velocities and the Si-overlayer defect densities. ( C) 1997 Elsevier Science Ltd.