Novel Oxide Trap Behavior in Ultra Thin Gate and Its Study by PDO Method

The degradation of MOSFETs under high field stress has been investigated for a l ong time. The degradation is due to the newly generated traps. As the gate thick ness scaled down rapidly, a conventional method for detecting oxide traps, such as C-V or subthreshold swing, is no longer effective. Some new phenome na a lso appear, such as Stress Induced Leakage Current (SILC) and soft-breakdown. T he oxide traps' behavior and their characteristics are the key problems in the s tudy of degradation. By extracting the change of transition coefficients from th e I-V curve and using the PDO (Proportional Differential Operator) meth od, various oxide traps can be distinguished and as would be helpful in the dete rmination of trap behavior changes during the degradation process.