AVS 47th International Symposium
    Electronics Tuesday Sessions
       Session EL-TuP

Paper EL-TuP3
Study of Electrical and Interfacial Properties of CVD-W/n-Si@sub 0.83@Ge@sub 0.17@/Si(001) Schottky Contacts

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: Y.C. Jang, Sungkyunkwan University, South Korea
Authors: Y.C. Jang, Sungkyunkwan University, South Korea
K.S. Kim, Sungkyunkwan University, South Korea
D.O. Shin, Sungkyunkwan University, South Korea
K.-H. Shim, Electronics and Telecommunications Research Institute, South Korea
S. Youn, Sungkyunkwan University, South Korea
K. Roh, Sungkyunkwan University, South Korea
Y. Roh, Sungkyunkwan University, South Korea
N.-E. Lee, Sungkyunkwan University, South Korea
Correspondent: Click to Email
The formation of metal contacts on Si@sub 1-x@Ge@sub x@ alloys plays an essential role in the various devices utilizing Si@sub 1-x@Ge@sub x@/Si including heterojunction bipolar transistors, and photodetectors. Therefore, interactions between the metals and the Si@sub 1-x@Ge@sub x@ layers are of technical and scientific interests for understanding of Schottky barrier formation. Chemical vapor deposited W as a refractory metal has been commonly used in microelectronics industry and has several characteristics that make it very attractive candidates for contact metallization. The effective Schottky barrier height measurements on the CVD-W/n-Si@sub 1-x@Ge@sub x@(001) system, however, have not reported so far as we know. In this study, we investigated the electrical properties of CVD-W/n-Si@sub 1-x@Ge@sub x@(x=0.17) and CVD-W/n-Si schottky contacts. Fully-strained 90-nm-thick n-type Si@sub 0.83@Ge@sub 0.17@ epitaxial thin film with the P concentration of 5x10@super 17@ cm@super -3@ was deposited on p-type Si(001) substrate at the substrate temperature of 650°C by LPCVD utilizing SiH@sub 4@, GeH@sub 4@, PH@sub 3@, and H@sub 2@ gases. W layers were grown by LPCVD using the WF@sub 6@, SiH@sub 4@, and H@sub 2@ at the growth temperature of 350 - 550°C. W Schottky contacts with various sizes from 0.2 mm@super 2@ to 0.5 mm@super 2@ were defined by photolithography and etching. Electrical properties of the CVD-W/n-Si@sub 0.83@Ge@sub 0.17@ Schottky diodes were characterized by I-V measurements in the forward-biased direction at room temperature. The measured effective Schottky barriers (@PHI@@sub Bn@) for CVD-W/n-Si@sub 0.83@Ge@sub 0.17@ and CVD-W/n-Si were 0.553 eV and 0.671 eV at the W deposition temperature (450°C).The structural, chemical and interfacial properties of CVD-W/n-Si@sub 1-x@Ge@sub x@(x=0.17) interfaces were analyzed by XRD, TEM, RBS, and AES. The correlation between electrical and structural properties of their interfaces will be discussed.