Effects of plasma characteristics on the thin film synthesis in one-component and two-component single phase systems

• Main Authors: Wen Yung Yeh, 葉文勇
• Other Authors: Jennchang Hwang
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/50836194887959722070

博士 === 國立清華大學 === 材料科學工程學系 === 89 === In this study, we discussed the effects of plasma characteristics on the synthesis of materials. Three major topics were included : (1) how the plasmas affect the deposition of one-component single phase diamond films, (2) how the plasmas affect the growth of one-component single phase AlN films, and (3) discussed the relation between the plasma and the oblique-cut surface by depositing diamond-like carbon (DLC) films on oblique-cut silicon substrates. At first, we used Langmuir probe and optical emission spectroscope (OES) to get the plasmas characteristics in the planar large-area microwave plasma source and RF plasma system. The electron density reached a maximum value of 4.4 x 1011 cm-3 at a 0.2 Torr pressure, and the electron temperature reached a minimum value of 0.4 eV under this condition. Because the higher electron density was considered as a better condition for we to proceed the deposition process, we deposited diamond films at this condition. We also used OES to get the major radicals composition in the CH4/CO2/H2 plasma were H、CH、OH and C2. In the diamond synthesis, we find that a deposition rate of 0.2mm/hr could be reached when the CH4 : CO2 : H2 = 6 : 12 : 100. The rate was more faster than other conditions by a factor of 7 because that the optimum radicals composition could be got under this condition. In the deposition of AlN films, we not only got the result that the deposition rate could be enhanced 25% by adding a ICP zone. We also got the deposition rate changed from 15.3 nm/min to 13.0 nm/min when the DC bias was switched from 8 V to -85 V. This is because that more radicals near the substrate surface could be created to enhance the deposition of AlN because more electrons could be created at more the positive DC bias condition. Finally, we deposited DLC on oblique-cut Si(111) substrates to discuss the effects of substrates on the growth mechanism and the structure of DLC films. We find composted DLC/SiC tips could be deposited when the terrace width was less than 21.1 A. The tip density was 25 μm-2 and 38 μm-2 on the substrate with the terrace width of 21.1 A and 14.4 A respectively. A speculation based on the formation of SiC spikes and electric field was provided to explain these results.