|Budget Amount *help
¥15,000,000 (Direct Cost: ¥15,000,000)
Fiscal Year 2002: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2001: ¥11,300,000 (Direct Cost: ¥11,300,000)
Atomic species such as H, C, N, F and Cl play important roles in gas-phase and surface reactions for various kinds of plasma material processing. In this project, we have developed a tunable VUV (vacuum ultra-violet) laser absorption spectroscopy system in the range from 800 to 1700 nm by using the two-photon resonant four-wave mixing method (ν_<VUV> = 2ν_1 + ν_2), and applied it to the diagnostics of those species in order to make clear the reaction mechanisms and obtain the guiding principles for the process control.
Following the quantitative measurement on F atoms, we applied the VUV absorption method Successfully to the measurement of C atoms in various kinds of fluorocarbon gas plasmas. The obtained results were analyzed for the role of C atoms in the etching of SiO_2 (see the paper published in J. Appl. Phys for more details). Then, we proceeded to the measurement of O atoms for better understandings of photo-resist ashing and Si oxidation processes.
For the measurements of H and N atoms, the wavelengths corresponding to ν_1 and ν_2 become 210 and 800 - 900 nm, respectively, for the VUV generation around 120 nm. Therefore, We have modified the laser system by substituting the pumping excimer laser with a YAG-laser for the better VUV conversion efficiency. As the result, we have succeeded in the measurement of H atoms in H_2 and CH_4 gases, and are continuing the quantitative measurement in the processing plasmas for the surface cleaning and diamond-like carbon deposition.