AVS 47th International Symposium
    Dielectrics Thursday Sessions
       Session DI+EL+MS-ThM

Paper DI+EL+MS-ThM11
Properties of SiO@sub 2@ Thin Films Deposited at Low Temperature on SiGe and Si Samples in O@sub 2@/TEOS Helicon Plasmas

Thursday, October 5, 2000, 11:40 am, Room 312

Session: Ultrathin Dielectrics and Interfaces
Presenter: A. Goullet, Institut des Matériaux Jean Rouxel, France
Authors: A. Goullet, Institut des Matériaux Jean Rouxel, France
D. Goghero, Institut des Matériaux Jean Rouxel, France
V. Fernandez, Institut des Matériaux Jean Rouxel, France
A. Granier, Institut des Matériaux Jean Rouxel, France
F. Meyer, Université de Paris XI, France
G. Turban, Institut des Matériaux Jean Rouxel, France
Correspondent: Click to Email
Silicon dioxide thin films are deposited at low pressure (< 5mTorr) and temperature (<200° C) on Si@sub 1-x@Ge@sub x@ epi-layers and silicon substrates in oxygen rich O@sub 2@/TEOS helicon plasmas. The growth of SiO@sub 2@ films and the evolution of the interfacial layer under applied radio frequency bias voltage (0, -100, -200 V) are investigated using a UV-Visible phase modulated ellipsometer (1.5-5 eV). The structural properties of the films are studied using infrared transmission spectroscopy, wet chemical etching and spectroscopic ellipsometry. Very thin (<10 nm) SiO@sub 2@ films deposited in the same conditions are investigated by X-ray photoelectron spectroscopy and spectroscopic ellipsometry to gain better insight of the oxide/semiconductor interface. The ion energy is found to be a significant parameter both for film properties and deposition rate. Use of radio frequency bias is effective in producing high quality SiO@sub 2@ films but an amorphized transition layer is detected in this case as evidenced by ellipsometric data modeling. The increase in the ion energy is also responsible for the presence of an additional oxidation state which appears on the Ge 3d XPS peak. Complementary capacitive C(V) measurements of grown oxides have been performed using metal-oxide-semiconductor samples. An increase in the fixed oxide charge and interface state densities as a function of the applied bias voltage is observed for silicon substrates whereas the electrical properties of the films deposited on Si@sub 1-x@Ge@sub x@ are rather insensitive to the deposition conditions.