AVS 45th International Symposium
    Manufacturing Science and Technology Group Monday Sessions
       Session MS-MoA

Paper MS-MoA4
Low-Temperature Large-Grain As-Deposited Poly-Si Formation by Microwave-Excited PECVD Using SiH@sub 4@/Xe

Monday, November 2, 1998, 3:00 pm, Room 317

Session: Contamination Free Manufacturing
Presenter: W. Shindo, Tohoku University, Japan
Authors: W. Shindo, Tohoku University, Japan
S. Sakai, Tohoku University, Japan
T. Ohmi, Tohoku University, Japan
Correspondent: Click to Email
We have achieved as-deposited large-grain polycrystalline silicon at a temperature of 300°C by plasma enhanced CVD using SiH@sub 4@/Xe. The grain size evaluated by X-ray diffraction is 25nm, which is believed to be the largest grain size among 100nm-thick as-deposited poly-Si films fabricated by various methods at low temperature. High-density (>10@super 12@cm@super -3@) plasma having very low electron temperature (approximately 1eV) excited by microwave irradiation was used for the film growth. Plasma density and electron temperature dominate ion flux density and ion kinetic energy incident on the substrate surface, respectively. Thus, high-flux and low-energy ion bombardment (<7eV) is realized in the system. Low-energy (<7eV), large-mass (Xe) ion bombardment on a growing film surface activates the film surface and successfully enhances the surface reaction/migration of silicon, resulting in high quality film formation at such a low temperature without inducing plasma damage in the film. Consequently, large-grain poly-Si growth is achieved at a temperature as low as 300°C. Therefore, low energy, high-flux, large-mass ion bombardment is a promising strategy for enhancing low-temperature poly-Si growth.