A new observation of the germanium outdiffusion effect on the hot carrier and NBTI reliabilities in sub-100nm technology strained-Si/SiGe CMOS devices

• Main Authors: Chung, S.S., Liu, Y.R., Yeh, C.F., Wu, S.R., Lai, C.S., Chang, T.Y., Ho, J.H., Liu, C.Y., Huang, C.T., Tsai, C.T.
• Format: Conference Proceeding
• Language: English
• Subjects: Charge pumps; CMOS technology; Degradation; Germanium silicon alloys; Hot carriers; Niobium compounds; Silicon germanium; Temperature dependence; Temperature sensors; Titanium compounds
• ISSN: 0743-1562
• DOI: 10.1109/.2005.1469222

In this paper, the evidence of SiGe layer induced trap generation and its correlation with enhanced degradation in strained-Si/SiGe CMOS devices have been reported for the first time. First, a new two-level charge pumping(CP) curve has been demonstrated to identify the Ge outdiffusion effect. Secondly, enhanced degradation in strained-Si devices has been clarified based on experimental results. Both n- and p-MOSFE's exhibit different extent of HC degradation effect. This is attributed to the difference in their mobility enhancement as well as additional traps coming from the Si/SiGe interface. Finally, temperature dependence of HC and NBTI has been examined for both strained-Si and bulk devices. Sophisticated measurement techniques, charge pumping and gated-diode (GD) measurements, have been employed to understand the generated interface traps. Results show that strained-Si device is less sensitive to the temperature and has a chance for better NBTI reliability if we have a good control of the strained-Si/SiGe interface, such as through low temperature gate oxide process or better S/D junction formation.