Defect formation mechanism during PECVD of a-Si:H

Conference · Tue Jul 01 04:00:00 EDT 1997

OSTI ID:20085534

Maeda, Keiji; Umezu, Ikurou

Defect formation mechanism in a-Si:H during PECVD at substrate temperature below 250 C is considered to be breaking of weak bonds in the Urbach tail. To break weak bonds, an extra energy is necessary. This energy is supplied by the reaction energy of SiH{sub 3} precursor at the growing surface incorporating SiH{sub 2} into the network. The defect density is experimentally shown to be proportional to a product of the energy supply frequency, i.e., SiH{sub 2} density, and the weak bond density which is obtained by the Urbach energy. By analysis using the configurational coordinate diagram the energy level of the broken weak bond is determined to be 0.2 eV above the valence band mobility edge. There is similarity of the defect formation mechanism during deposition to that of the Staebler-Wronski effect.

• Research Organization: Science Univ. of Tokyo, Noda, Chiba (JP)
• OSTI ID: 20085534
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
CHEMICAL BONDS
CHEMICAL VAPOR DEPOSITION
CRYSTAL DEFECTS
ENERGY LEVELS
HYDROGEN ADDITIONS
SILICON