Development of real-time spectroscopic ellipsometry and its application to the growth and modification of amorphous silicon thin films

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:7139720

An, I

A rotating polarizer type real-time spectroscopic ellipsometry (RTSE) with a multichannel detection system has been developed to investigate dynamical changes in microstructure and optical properties during the growth and processing of thin films. The performance of this new detection system has been diagnosed in detail and unique techniques have been developed to characterize and correct various errors. The RTSE has been employed in a real-time investigation of the growth mechanism of thin amorphous silicon films prepared by various techniques under different conditions. In these studies the nucleation stage, monolayer formation, coalescence, and bulk film growth in each film were identified. Also bulk dielectric functions and optical gaps were deduced from real-time spectra. Finally post-hydrogenation experiments were performed in situ on the as-grown samples. Atomic hydrogen (H) was generated by a hot tungsten filament. The post-hydrogenation process was monitored through the changes in optical properties and this process was interpreted as reaction-limited rather than diffusion-limited. In addition, post-hydrogenation experiments were carried out on oxide covered amorphous silicon films, where oxide thicknesses were estimated as several monolayers. In this study the ultrathin oxide layers were found to be very strong barriers to H diffusion. This may indicate that hydrogen enters the silicon network via silicon-hydrogen bonding on the surface rather than via interstitial states. Also this phenomena implies the importance of performing post-hydrogenation in situ.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States)
• OSTI ID: 7139720
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
36 MATERIALS SCIENCE
SILICON
ELLIPSOMETRY
HYDROGENATION
MICROSTRUCTURE
AMORPHOUS STATE
EPITAXY
OPTICAL PROPERTIES
REAL TIME SYSTEMS
CHEMICAL REACTIONS
ELEMENTS
MEASURING METHODS
PHYSICAL PROPERTIES
SEMIMETALS
664200* - Spectra of Atoms & Molecules & their Interactions with Photons- (1992-)
360602 - Other Materials- Structure & Phase Studies