Formation of silicon on insulator using separation by implantation of oxygen with water plasma

Separation by plasma implantation of oxygen (SPIMOX) was developed to fabri cate silicon-on-insulator (SOI) wafers based on separation by implantation of oxygen technology, however, it suffers from the coexistence of O+ and O- 2(+) ions in the oxygen plasma, which gives rise to nonuniformity of the fo rmed buried oxide layer. In the present work, water plasma was used as a so urce of oxygen (H2O+, HO+, and O+) for achieving small spread in the oxygen implant depth profile. The feasibility of SPIMOX with water plasma to form SOI wafers was explored at an ion implanter without mass separator. Cross- sectional transmission electron microscopy revealed that a uniform buried o xide layer was formed under a single crystal silicon overlayer with the pre sent process. The interfaces between the silicon overlayer, buried oxide la yer, and bulk silicon were smooth and sharp. An implant dose window has bee n identified for producing a desirable SOI structure. (C) 2001 American Ins titute of Physics.