AVS 46th International Symposium
    Electronic Materials and Processing Division Friday Sessions
       Session EM-FrM

Paper EM-FrM10
The Deposition of Polycrystalline Si and SiGe by Ultra-high Vacuum Chemical Vapor Deposition System

Friday, October 29, 1999, 11:20 am, Room 608

Session: In Situ Monitoring and Growth
Presenter: K.M. Chen, National Chiao Tung University, Taiwan, R.O.C.
Authors: K.M. Chen, National Chiao Tung University, Taiwan, R.O.C.
H.J. Huang, National Chiao Tung University, Taiwan, R.O.C.
L.P. Chen, National Nano Device Laboratory, Taiwan, R.O.C.
G.W. Huang, National Nano Device Laboratory, Taiwan, R.O.C.
C.Y. Chang, National Chiao Tung University, Taiwan, R.O.C.
Correspondent: Click to Email
The polycrystalline Si@sub 1-x@Ge@sub x@ (poly-Si@sub 1-x@Ge@sub x@) films have better properties than poly-Si for device fabrications, such as lower transition temperature and process thermal budget. For these reasons, the poly-Si@sub 1-x@Ge@sub x@ films have been utilized for low-temperature TFT fabrications and gate electrodes of MOS transistors. In this work, disilane and germane were used to grow poly-Si@sub 1-x@Ge@sub x@ films at low temperature (<600°C) by cold-wall type ultra-high vacuum chemical vapor deposition (UHV/CVD) system . The poly-Si@sub 1-x@Ge@sub x@ films were deposited on oxide and nitride surfaces. The Ge content x was evaluated from X-ray diffractometry and AES, it is observed that the Ge content increases with the increase of the GeH@sub 4@ flow rate. The result is only slightly related to the substrate type. The growth rate increases with the Ge content at lower values and then decreases with the Ge content in the higher composition range (x>0.1). This implies that the growth mechanism of poly-Si@sub 1-x@Ge@sub x@ films is different from that of epitaxial Si@sub 1-x@Ge@sub x@ on Si. The uniformity of poly-Si@sub 1-x@Ge@sub x@ films depends on the Ge content, and it is improved by the addition of germanium. The result can be explained by the lower activation energy (< 0.25 eV) related to deposition of poly-Si@sub 1-x@Ge@sub x@, as compared to that of poly-Si (~2.1eV) in the surface-reaction limited growth mode. From the XRD and AFM analyses, the crystallinity and roughness of films are suitable to device fabrications.