Interface state buildup by high-field stressing in various metal-oxide-semiconductor insulators using deep level transient spectroscopy

The buildup of interface states with high field (HF) stressing have been observed in thermally grown oxide, N2O nitrided oxide (NO), and reoxided nitrided oxide (RNO). The DLTS technique was used to analyze the electronic properties of the Si/SiO2 interface. We show that N2O nitridation of SiO2 changes the electronic distribution of states at the Si/SiO2 interface after HF electrical stress. Our results indicate that this nitrogen plays an important role in preventing the creation of a center at Et1=0.34 eV below the bottom of the conduction band. However, the nitrogen is responsible for a new level at Et2=0.22 eV below the bottom of the conduction band after the NO device is stressed. Also, reoxidation and increasing time of the reoxidation shift the maximum of the peak level away from the Et2 toward Et1.