Quality Improvement of Ultrathin Gate Oxide by Using Thermal Growth Followed by SF ANO Technique

Rapid thermal oxide followed by anodization in direct
current superimposed with scanning frequency alternating current
was demonstrated for the first time to have an improved quality
in ultrathin gate oxides. Compared with the thermal oxide grown
without the scanning-frequency anodization (SF ANO) treatment,
the gate leakage current density ( ) of SF ANO sample is significantly
reduced without increasing the thickness of gate oxide. In
addition, it could be observed that the interface trap density ( it)
is reduced with tighter distribution. It is suggested that the bulk
traps and interface traps in thermally grown oxide can be repaired
during the SF ANO process.