AVS 58th Annual International Symposium and Exhibition
    Plasma Science and Technology Division Thursday Sessions
       Session PS-ThP

Paper PS-ThP3
Reaction Process of Si Surfaces with Hydrogen Plasma

Thursday, November 3, 2011, 6:00 pm, Room East Exhibit Hall

Session: Plasma Science and Technology Poster Session
Presenter: Ko-jiro Hara, Nagasaki University, Japan
Authors: K. Hara, Nagasaki University, Japan
M. Shinohara, Nagasaki University, Japan
Y. Takami, Nagasaki University, Japan
Y. Takaki, Nagasaki University, Japan
Y. Matsuda, Nagasaki University, Japan
H. Fujiyama, Nagasaki University, Japan
Correspondent: Click to Email
Hydrogen plasma generates hydrogen radicals and ions in it. Both of them are important to Si technologies, such as the deposition of Si-related films, the etching of the films and so on; hydrogen radicals generate the adsorption sites by abstracting hydrogen from hydrogen terminated Si surface, while hydrogen radicals terminated dangling bonds of Si films. On the other hand, hydrogen ions also play an important role in Si etching process. Then, it is important to investigate the reaction process of hydrogen plasma with Si surfaces. We investigated the reaction processes at the different substrate bias conditions. The processes were investigated with infrared spectroscopy in multiple internal reflection geometry (MIR-IRAS). Hydrogen plasma was generated by feeding RF (13.56 MHz) power to the coil wrapped the glass tube. Hydrogen plasma was exposed to chemical oxide covered Si(100) surfaces. After the oxide layer was etched, the surface was terminated with hydrogen. Moreover, the surface was distorted, so that the atomic arrangements on the surface were changed into amorphous layer. With the increase of substrate bias which was fed with RF (800kHz) power, the formation of the amorphous layer was increased. Furthermore, we noticed that the main peak position was changed with the exposure in this process; in the initial stage, the main peak was observed between 2000 and 2030 cm-1. In the middle stage the main peak was located at 2060 cm-1. In the final stage the main peak was located at 2100 cm-1. From the assignment of the peak positions, amorphous SiH components were formed in the initial stage; amorphous SiH2 components were formed in the final stage. The peak at 2060 cm-1 observed in the middle stage can be assigned to the distorted SiH or hydrogen terminated vacancy. It is suggested that the kinds of hydride components are changed with the exposure.