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 (J/sub g/) 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 (D/sub 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.