Spectroscopic Ellipsometry of 3C-SiC Thin Films Grown on Si Substrates Using Organosilane Sources

• Published in: Japanese Journal of Applied Physics 2005-06, Vol.44 (6R), p.4015
• Main Authors: Kubo, Naoki, Moritani, Akihiro, Kitahara, Kuninori, Asahina, Shuichi, Kanayama, Nobuyuki, Tsutsumi, Koichi, Suzuki, Michio, Nishino, Shigehiro
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.44.4015

Dielectric function spectra of 3C-SiC films on Si substrates in the energy region of 0.73–6.43 eV were measured by spectroscopic ellipsometry. Hexamethyldisilane (Si 2 (CH 3 ) 6 ) and tetraethylsilane (Si(C 2 H 5 ) 4 ) were used as safe organosilane sources for the growth of SiC films. The measured spectra were compared with those of 3C-SiC on a Si(001) substrate grown with disilane (Si 2 H 6 ). First, the pseudodielectric function spectra gave a shoulder structure corresponding to the direct X 5 – X 1 interband transition in the Brillouin zone. Secondly, the dielectric function of 3C-SiC was determined by applying a four-layer model in which we took into account the surface roughness and mixed crystals of a carbonized interface layer. Finally, the third-derivative lineshape of the imaginary part ε 2 of the complex-dielectric function provided the values of the interband transition energy E g and the broadening parameter Γ for the X 5 – X 1 interband transition. The measured values of Γ indicated that the crystalline quality of SiC films grown using organosilane sources is comparable to that of SiC films grown using Si 2 H 6 .