Properties of silicon-on-defect-layer material

A new silicon material, silicon-on-defect-layer (SODL), has been measured by secondary ion mass spectrometry (SIMS) and spreading resistivity (SR) measurements. SIMS data show that the buried defect-layer in SODL consists of silicon oxide due to the gettering of intrinsic oxygen by proton-implanted damage. Furthermore, SODL procedure makes a silicon wafer contain much fewer oxygen in surface-layer on the defect-layer, resulting in a purified surface-layer. Measurements of SR indicate that the surface-layer of n-type silicon wafer was converted to p-type silicon after SODL procedure. A metal oxide semiconductor (MOS) device with a value of the electron mobility in the inversion mode of 714 cm²/(V · s) was fabricated on SODL material. Like isolation function of a well in a complementary MOS (CMOS) device, the p-n junction in SODL material could play a role of isolation between the surface-layer and bulk. In addition, by reducing the implantation energy, SODL technology for making p-n junction, in which built-in field separates light-generated electrons and holes, is a candidate to make cheap solar cells by using low-quality low-cost silicon.