Title :
Off-state gate current in n-channel MOSFETs with nitrided oxide gate dielectrics
Author :
Wu, Albert T. ; Lee, Shiuh-Wuu ; Murali, V. ; Garner, Michael
Author_Institution :
Intel Corp., Santa Clara, CA, USA
Abstract :
The authors report on the off-state gate current (I/sub g/) characteristics of n-channel MOSFETs using thin nitrided oxide (NO) gate dielectrics prepared by rapid thermal nitridation at 1150 degrees C for 10-300 s. New phenomena observed in NO devices are a significant I/sub g/ at drain voltages as low as 4 V and an I/sub g/ injection efficiency reaching 0.8, as compared to 8.5 V and 10/sup -7/ in SiO/sub 2/ devices with gate dielectrics of the same thickness. Based on the drain bias and temperature dependence, it is proposed that I/sub g/ in MOSFETs with heavily nitrided oxide gate dielectrics arises from hot-hole injection, and the enhancement of gate current injection is due to the lowering of valence-band barrier height for hole emission at the NO/Si interface. The enhanced gate current injection may cause accelerated device degradation in MOSFETs. However, it also presents potential for device applications such as EPROM erasure.<>
Keywords :
hot carriers; incoherent light annealing; insulated gate field effect transistors; leakage currents; nitridation; 10 to 300 sec; 1150 degC; 4 V; EPROM erasure; SiO/sub x/N/sub y/-Si; accelerated device degradation; drain bias; drain voltages; gate current injection; hole emission; hot-hole injection; injection efficiency; n-channel MOSFETs; nitrided oxide gate dielectrics; off-state gate current; rapid thermal nitridation; temperature dependence; valence-band barrier height; Dielectric devices; Electrons; Hot carriers; Implants; Low voltage; MOSFETs; Rapid thermal processing; Silicon; Temperature dependence; Tunneling;
Journal_Title :
Electron Device Letters, IEEE
