Conduction type change with annealing in thin silicon-on-insulator wafers

Carrier concentration profiles of p-type thin silicon-on-insulator (SOI) wafers fabricated by oxygen ion implantation and wafer bonding are measured using spreading resistance analysis. SOI layers are almost fully depleted for the as-received wafers. With annealing at 1000 and 600 degreesC for 240 min, the carrier concentration profiles are not changed significantly, while with annealing at 700-800 degreesC for 240 min, carrier concentration in the SOI layer increases up to the order of 1 x 10(16) cm(-3). From current-voltage, capacitance-voltage and Hall measurements, it is found that the conduction type of the SOI layers annealed at 700-800 degreesC for 240 min are inverted into n-type and that the level of donor generated by the annealing is shallower than 0.03 eV below the conduction band. (C) 2004 Elsevier Ltd. All rights reserved.