Memory characteristics of Ge1−xSix/Si hetero-nanocrystals in metal-oxide-semiconductor structures

Memory characteristics in the metal-oxide-semiconductor (MOS) structure based on Ge
_1-x
Si
_x
/Si hetero-nanocrystals (HNCs) have been investigated experimentally and theoretically. The Ge
_1-x
Si
_x
/Si HNCs on ultrathin SiO
₂
were fabricated through combining self-assembled growth and selective chemical etching technique. The observations demonstrate that the holes reach a longer retention time even with an ultrathin tunnel oxide, owing to the high band offset at the valence band between Ge and Si.