AVS 51st International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeA

Paper TF-WeA1
Structural, Electrical and Optical Properties of Transparent Conductive In@sub 2@O@sub 3@-SnO@sub 2@ Films

Wednesday, November 17, 2004, 2:00 pm, Room 303C

Session: Transparent Conducting Oxides
Presenter: Y. Sato, Aoyama Gakuin University, Japan
Authors: Y. Sato, Aoyama Gakuin University, Japan
R. Tokumaru, Aoyama Gakuin University, Japan
K. Utsumi, Tosoh Corporation, Japan
H. Iigusa, Tosoh Corporation, Japan
P.K. Song, Aoyama Gakuin University, Japan
Y. Shigesato, Aoyama Gakuin University, Japan
Correspondent: Click to Email
Transparent conductive In@sub 2@O@sub 3@-SnO@sub 2@ films were deposited by dc magnetron sputtering using high density ceramic targets which contained various SnO@sub 2@ contents (0-100 wt.%) on unheated glass substrates. These films were post-annealed under various atmospheres (Air, Ar or Ar+3%H@sub 2@) at 200 @super o@C for 1 hr. The structural, electrical and optical properties of these films were investigated. XRD profiles of all the as-deposited films exhibited amorphous structure. After post-annealing under various atmospheres, XRD profiles of the films deposited using targets of up to 20% SnO@sub 2@ contents showed bixbyte crystal structures of In@sub 2@O@sub 3@, whereas all the films deposited using the targets of SnO@sub 2@ contents higher than 20 wt.% showed amorphous structure. Resistivity of the films deposited using the targets of up to 20% SnO@sub 2@ contents was reduced from about 400 to 200 @micro@@ohm@cm by post-annealing under each condition, because carrier density increased with increasing the number of the substitutional Sn@super 4+@ at In@super 3+@ site as the result of the crystallization. All the post-annealed films possessed high transmittance of over 80 % in the region of visible light. In the region of over 1000 nm, the transmittance decreased with increasing Sn concentration, where reflectance increased. Work functions of the all films were analyzed by electron spectroscopy in air (ESA, AC-2). The work function of the films showed clear negative relationship to the carrier density. This could be explained in terms of the shift of the Fermi level to the higher energy in conduction band with the increasing carrier density.