AVS 51st International Symposium
    Electronic Materials and Processing Monday Sessions
       Session EM-MoP

Paper EM-MoP4
Investigation of Thermal Stability of Strained Si on Relaxed SiGe Layer

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

Session: Poster Session
Presenter: N.-E. Lee, Sungkyunkwan University, South Korea
Authors: C.H. Jang, Sungkyunkwan University, South Korea
J.W. Lee, Sungkyunkwan University, South Korea
C.W. Yang, Sungkyunkwan University, South Korea
M.R. Sardela Jr., University of Illinois at Urbana-Champaign
Y.J. Song, Electronics and Telecommunications Research Institute, Korea
K.-H. Shim, Electronics and Telecommunications Research Institute, Korea
N.-E. Lee, Sungkyunkwan University, South Korea
Correspondent: Click to Email
MOSFET device utilizing a strained-Si channel on relaxed SiGe buffer layer is one of the most promising structure for the next-generation CMOS integration scheme below 50 nm technology node because of enhanced channel mobility and compatibility with conventional Si CMOS processes. For the practical adoption of strained-Si channels into nano-CMOS technology, fabrication methods of strained-Si/relaxed SiGe/Si structures and their compatibility with post-thermal processes are to be obtained. In particular, stability of strained-Si channels on relaxed SiGe layers is of great concern because formation of misfit and threading dislocations and increase of surface roughness can occur during elevated temperature processing due to thermal-induced instability of strained-Si layers. In this study, we investigated thermal stability of strained-Si on relaxed SiGe layer at elevated RTA (rapid thermal annealing) temperatures. Strained-Si channel layers on the relaxed Si1-xGex(x=0.2) buffer layer were deposited by reduced-pressure chemical vapor deposition (RP-CVD). In order to investigate the thermal stability of fabricated strained-Si/relaxed-SiGe/Si(001), RTA treatments were carried out at the temperature range of 700~950°C in N@sub 2@ ambient for 60sec. Strain relaxation behaviors of strained-Si layer were investigated using Raman spectroscopy and reciprocal space mapping (RSM). Analyses of defect formation and structure of strained-Si were also performed by analytical transmission electron microscopy (AEM). And evolution of surface roughness and morphology upon RTA was measured using atomic force microscope (AFM) and field-emission scanning electron microscopy (FE-SEM). The combined results indicate that strained-Si is unstable due to strain relaxation leading to defect formation and increased surface roughness at the RTA temperature ï,³ 900 oC in the present experiments. Detailed results on strain relaxation behaviors of the strained-Si will be presented.