Investigation of Si nanocluster formation in sputter deposited silicon suboxides and application to nanocluster memory structures

Silicon rich silicon oxide films (SRO) were prepared by co-sputtering from silica and silicon targets in an argon atmosphere. The formation of silicon nanoclusters (Si NCs) by a thermally stimulated phase separation was
investigated. The influence of sample composition and annealing temperature has been studied by optical methods (infrared absorbtion and photoluminescence). Both methods reveal that phase separation proceeds
more quickly in SRO films with a higher Si excess. Additionally MOS capacitors with embedded Si NCs were prepared and investigated by capacitance-voltage measurements.
The embedded Si NCs could be charged by direct tunneling. For optimized samples held at flat-band potential, the charge loss after 2 days at room temperature was below 10%.