Monday, November 29, 2010

US Patent 7838422 - Al-doped nanodot FET

Silicon nanodots used to form charge trap layers in non-volatile memory have been found to produce unstable retention characteristics. This patent from Samsung teaches using aluminum doping to improve retention. Claim 1 reads:

1. A method of forming a charge trap layer structure comprising:

forming an amorphous silicon film on a tunneling film;

forming a charge trap layer having a plurality of silicon nano dots and a silicon oxide layer covering the silicon nano dots by partially oxidizing the amorphous silicon film; and

doping the charge trap layer with aluminum (Al) at a concentration of about 0.1 to about 10 atom %.