AVS 56th International Symposium & Exhibition
    Electronic Materials and Processing Tuesday Sessions
       Session EM-TuP

Paper EM-TuP24
A Study on the In-Situ Phosphorus-Doped epi-Si1-xCx Growth for NMOSFET Application

Tuesday, November 10, 2009, 6:00 pm, Room Hall 3

Session: Electronic Materials and Processing Poster Session
Presenter: J.-H. Yoo, Yonsei University, Korea
Authors: J.-H. Yoo, Yonsei University, Korea
D.-K. Lee, Yonsei University, Korea
D.-H. Ko, Yonsei University, Korea
Correspondent: Click to Email
As the size of complementary metal oxide semiconductor (CMOS) technology devices scales down, studies on strained channel engineering using lattice mismatch have received considerable attention since conventional structures shows serious problems, such as the increase of leakage current and the decrease of channel mobility. Specifically, in order to improve the electron mobility in the channel for NMOSFETs, many researches about source/drain epi-Si1-xCx are in progress because of the successful employment of source/drain epi-Si1-xGex in PMOSFETs. However, due to the extremely low solid solubility of C in Si in thermodynamic equilibrium, it is difficult to grow epi-Si1-xCx with x > 1 at %. Furthermore, thermal annealing processes for the electrical activation of source/drain implants after the epi-Si1-xCx growth can easily precipitate C atoms out from the substitutional sites, causing the loss of stress and affecting the junction and transport properties. In-situ doped epi-Si1-xCx can maintain the strained Si1-xCx layers with heavy doping because the process need not contain ion implantation and activation annealing. In this paper, we investigated the formation and the thermal stability of in-situ Phosphorus doped epi-Si1-xCx in order to apply these films to the source/drain region of the ULSI device. The native oxide on Si (100) wafers was completely removed by HF cleaning and 100 nm-thick Phosphorus doped Si1-xCx films were immediately deposited by UHV-CVD. Disilane (Si2H6), monomethlysilane (SiH3CH3) and phosphine (PH3) gases were used for Si, C and P sources, respectively. The strains of the Si1-xCx layer were investigated by using HR-XRD. The microstructures were observed by using HR-TEM.