AVS 50th International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP1
Silicon Dioxide Etching Processes Employing Electron Beam Excited Plasmas

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: M. Ito, Wakayama University, Japan
Authors: M. Ito, Wakayama University, Japan
K. Takeda, Wakayama University, Japan
Y. Tomekawa, Wakayama University, Japan
M. Iwawaki, Wakayama University, Japan
T. Shiina, Wakayama University, Japan
Y. Okamura, Wakayama University, Japan
M. Hori, Nagoya University, Japan
T. Goto, Nagoya University, Japan
Correspondent: Click to Email
Optical devices or micro total analysis system fabricated by using micromachining techniques attract much attention because of their usefulness. In the fabrication processes, micromachinings of non-planer thick dielectric materials such as optical fibers and thick quartz parts are necessary. In such processes, the fast atomic beam etching and ion beam etching are employed because the RF self-biasing in the conventional reactive ion etching (RIE) is not applicable to non-planer dielectric materials such as silicon dioxide (SiO@sub 2@). However, the etch rates of these processes are typically around few tens nm/min, which are very low compared with the RIE and so the higher etch rate is strongly required to reduce the processing time. Therefore, the biasing effect is necessary to etch the SiO@sub 2@. On the other hand, an electron beam excited plasma (EBEP) has an excellent potential for applying self-bias to the non-planer dielectrics by using the electron beam. The SiO@sub 2@ etching characteristics using EBEP have been never reported although the SiO@sub 2@ is useful for the devices using micromachining techniques. Therefore, we have demonstrated the SiO@sub 2@ etching processes using self-biasing induced by an electron beam of the EBEP without any additional bias power supply. As a source gas, the CF@sub 4@ diluted by Ar (CF@sub 4@/Ar) was employed. The etch rate of 117 nm/min has been obtained. From the plasma diagnostics using a Langmuir probe and an optical emission spectroscopy, it has been found that the higher electron beam current for generating plasmas improves the plasma density and sheath potential, resulting in higher etch rate of SiO@sub 2@. Moreover, novel pulsed EBEPs have been applied for the SiO@sub 2@ etching process. The plasma diagnostics have been carried out. These results indicated that the electron beam excited plasmas has a great potential for application to micromachining processes.