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

Paper EM-MoP2
Nickel Silicide Formation and Strain Relaxation of SiGe Layers during Rapid Thermal Annealing of Ni/cap-Si/Si0.83Ge0.17/Si(001) Structure

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

Session: Poster Session
Presenter: C.H. Jang, Sungkyunkwan University, South Korea
Authors: C.H. Jang, Sungkyunkwan University, South Korea
Y.W. Kim, Seoul National University, 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
NiSi or NiSi@sub 1-y@Ge@sub y@ has been intensively investigated for contact applications in CMOS devices utilizing strained Si or SiGe layers for better device performance. Recently, NiSi@sub 1-y@Ge@sub y@ layers formed from the direct reaction of Ni/SiGe structure showed a better thermal stability but a rough interface compared to NiSi on Si substrate. Therefore, NiSi/SiGe structure with improved interface flatness for a better control of the ultra-shallow depth of contacts needs to be investigated. In this study, the electrical and structural characteristics of nickel silicides formed on p-Si@sub 0.83@Ge@sub 0.17@/Si (001) using a sacrificial Si capping layer (cap-Si) and strain relaxation of SiGe layers during nickel silicidation were investigated. The phase formation of nickel silicide and interface quality between nickel silicide and the SiGe layer were measured by XRD (X-ray diffraction) and TEM (transmission electron microscopy), respectively. Sheet resistance of nickel silicide on p-Si@sub 0.83@Ge@sub 0.17@ /Si(001) substrate was investigated by four-point probe measurements. Chemical composition and depth profile of nickel silicide was examined by AES (auger electron spectroscopy). The surface roughness of nickel silicide films was measured using AFM (atomic force microscope) and surface morphology by FE-SEM (field-emission scanning electron microscopy). Strain relaxation behaviors of SiGe layers during Ni silicidation were investigated by high-resolution XRD and reciprocal space mapping (RSM) study. The results showed the formation of nickel monosilicide at 400~550°C and the sheet resistance values of 6.533 ~7.918 @ohm@/sq. But, increase in sheet resistance values above T@sub A@ @>=@600°C is attributed to the formation of high-resistivity silicide phase and surface roughening by agglomeration of nickel silicides. Detailed changes in lattice parameters and mismatch in the SiGe layers will be presented.