Effects of Interface States and Positive Charges on NBTI in Silicon-Oxynitride p-MOSFETs

Abstract

p-MOSFET negative bias temperature instability (NBTI) has become the most critical reliability issue for state-of-the-art CMOS technology. This paper investigates the effects of interface states (Nit) and oxide positive charges (PCs) on NBTI. Evidence shows how the importance of and PC is affected by stress temperature. PC has a dominative contribution to the NBTI at lower temperatures (< 373 K), whereas increases obviously above 373 K. Two kinds of PC are distinguished by the generation and recovery dynamics. One is the trapped holes (THs) which is the main part of PC at lower temperatures. The other is the generated PC of which generation is accelerated by temperature. NBTI recovery mainly results from TH detrapping. To find out the hole's influence on NBTI, the hole-injection and hole-energy effects on and PC formation are studied. It will be shown that the case is different to and PC. In addition, on-the-fly technique is used to eliminate the recovery during measurements. Analysis shows that is unimportant and that PC dominates the NBTI when measured by the nonrecovery technique. Moreover, the behaviors of TH, such as saturation and temperature independent, are also explained in this paper.