Contactless measurement of the Si - Buried oxide interfacial charges in SOI wafers with surface photovoltage technique.

Surface Photovoltage Technique has been employed to image distribution of the oxide charges present at the Si active layer - buried oxide interface in its vicinity. SOI substrates fabricated by oxygen ion implantation and by wafer bonding have been compared. Oxygen implanted wafers exhibited larger and less uniformly distributed charges than the comparable bonded substrates. Charge density and distribution uniformity was dependent on the oxygen implant dose. Measured charges were not affected by the annealing imitating device processing heat cycle. Demonstrated charge imaging technique could offers an effective way for the SOI substrate screening.