AVS 51st International Symposium
    Dielectrics Monday Sessions
       Session DI-MoP

Paper DI-MoP3
Characteristics of Mo@sub x@Si@sub y@ Gate Electrodes for Advanced CMOS Applications

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: P. Sivasubramani, University of Texas at Dallas
Authors: P. Sivasubramani, University of Texas at Dallas
P. Zhao, University of Texas at Dallas
I.S. Jeon, University of Texas at Dallas
J. Lee, Kookmin University, Korea
J. Kim, Kookmin University, Korea
M. Kim, University of Texas at Dallas
B.E. Gnade, University of Texas at Dallas
R.M. Wallace, University of Texas at Dallas
Correspondent: Click to Email
Metal gates have been investigated to overcome several challenging issues such as poly-depletion and B penetration for conventional poly-Si gates. Recently, the dual metal gate approach has attracted attention to improve CMOS performance, as opposed to mid-gap metals, such as TiN and TaN. For CMOS integration, tunable metals may be suitable for metal gate applications. Alloying and implantation are being considered as possible techniques to tune the metal gate workfunction. In particular, silicidation is an acceptable process for Si IC fabrication. In this study, we investigated the characteristics of the Mo-Si alloy system for dual metal gate applications. Mo has been demonstrated as a possible P-MOS gate metal because of its high work function and good thermal stability. In this presentation we focus on the tunability of work function, thermal stability and electrical characteristics of Mo silicide as a function of Si concentration. Mo silicide has three different stable silicide phases, Mo@sub 3@Si, Mo@sub 5@Si@sub 3@ and MoSi@sub 2@. Mo silicide samples were prepared on SiO@sub 2@ on Si wafers. The samples were annealed by RTA for 15sec. up to 1000°C. We observed metal work function tuning of at least 0.5V by changing the composition. We also found a possible thermal instability issue of MoSi@sub 2@, even at room temperature. The dependence of characteristics on composition will be discussed based on XPS, XRD, RBS, TEM, CV and IV results. This work is partially supported by the TATP (Texas Advanced Technology Program) and COSAR (Collaborate Project for Excellence in Basic System IC Technology-Korea).