Qy. Tong et al., ULTRATHIN SINGLE-CRYSTALLINE SILICON ON QUARTZ (SOQ) BY 150-DEGREES-CWAFER BONDING, Sensors and actuators. A, Physical, 48(2), 1995, pp. 117-123
Single-crystalline silicon films with thicknesses as thin as 2000 Angs
trom have been prepared on thermally mismatched quartz substrates by a
simple wafer-bonding approach. Initial bonding at approximate to 80 d
egrees C, storage at room temperature for more than 100 h and multi-te
mperature (maximum 150 degrees C) consecutive annealing with a 1 degre
es C min(-1) ramping rate have been adopted to strengthen the bond and
to prevent debonding at the edge of the bonded pairs during annealing
and etching, where thermal shearing and peeling stresses are maximum.
Final etching by EDP (ethylenediamine-pyrocatechol-water) effectively
reduces the peeling failure of the highly stressed thinned silicon la
yer, mainly due to a reduced lateral oxide etching rate along the inte
rface. The high carrier mobility in the single-crystalline silicon lay
er and the transparent and insulating quartz substrate provides a new
dimension of freedom in applications.