SOI wafers with 30-100 A buried oxide (box) created by wafer bonding using 30-100 A thin oxide as bonding layer

A method of fabricating a silicon-on-insulator wafer comprising the steps of:

• forming a substantially uniform thermal oxide film on a Si-containing layer of a silicon-on-insulator substrate, said thermal oxide film having a hydrophilic surface and said substrate having a buried oxide region positioned between said Si-containing layer and an underlaying Si-containing substrate;
• positioning a carrier wafer having a hydrophilic surface such that the hydrophilic surfaces of the thermal oxide film and the carrier wafer adjoin each other;
• bonding said hydrophilic surfaces together at about room temperature to provide a bonded structure;
• annealing said bonded structure to form a sacrificial oxide on exposed Si surfaces of said bonded structure;
• selectively removing said sacrificial oxide and said Si-containing substrate from said bonded structure to expose said buried oxide region;
• and
• selectively removing said exposed buried oxide region to provide a SOI wafer that comprises said thermal oxide film sandwiched between the Si-containing layer of the SOI substrate and the carrier wafer.