서지주요정보
마이크로웨이브 플라즈마 화학증착법에 의한 다이아몬드 박막의 Heteroepitaxy 성장에 관한 연구 = The study on the heteroepitaxial growth of diamond films synthesized by microwave plasma enhanced chemical vapor deposition
서명 / 저자 마이크로웨이브 플라즈마 화학증착법에 의한 다이아몬드 박막의 Heteroepitaxy 성장에 관한 연구 = The study on the heteroepitaxial growth of diamond films synthesized by microwave plasma enhanced chemical vapor deposition / 김윤기.
저자명 김윤기 ; Kim, Yoon-Kee
발행사항 [대전 : 한국과학기술원, 1997].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8007400

소장위치/청구기호

학술문화관(문화관) 보존서고

DMS 97008

휴대폰 전송

도서상태

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초록정보

The highly oriented diamond films are deposited on the mirror-polished (100) silicon substrates in microwave plasma deposition system using a three-step process consisting of carburization, bias-enhanced nucleation(BEN) and growth. In order to establish the selective growth condition of oriented nuclei formed during BEN step, texture-controlled diamond films are deposited on silicon wafers in a $CH_{4}-H_{2}$ gas mixture and the quality of the textured films is investigated using Raman spectroscopy. It is found that the quality of the (100) textured film is better than those of (110) or (111) textured films. The optimum growth rate maintaining the (100) texture is about 0.6 m/h, and its deposition conditions are as follows: substrate temperature, 800℃; methane concentration, 2%; microwave power, 1000W. By adjusting the geometry of the substrate and substrate holder, very dense disc-shaped plasma is formed over the substrate when the bias voltage is about -250V. This dense plasma is a prerequisite for the high orientation and is not obtained simply by increasing microwave power, but is obtained by introducing a graphite block between the substrate and the substrate holder. From the results of the optical emission spectra of the dense disc-shaped plasma, it is found that the concentration of atomic hydrogen and hydrocarbon radicals are increased with negative bias voltage. It is also found that the highly oriented diamonds are deposited in the region, where the intensity ratios of carbonaceous species to atomic hydrogen are saturated. The surface of highly oriented diamond film is composed by rectangular shaped grains which are formed parallel to each other. The {111} diamond pole figure of the film is clearly four-fold symmetry as expected for an epitaxial film. The full width at half maximum(FWHM) in the azimuthal angle and pole angle of the {111} diamond pole is about 9℃. The FWHM of the x-ray rocking curve of the diamond (004) reflex from the film is also about 9℃. During the BEN process, a positive hydrogen ions and carbonaceous ions bombard to the substrate. Silicon atoms may be preferentially removed from the surface and near-surface layers of the silicon carbide deposited on silicon substrate. In order to sustain the lattice structure of silicon carbide, some of the carbonaceous ions fill in the vacant silicon sites immediately after the silicon atoms are etched. In this manner, the $sp^3$-bond carbon clusters can be formed with the orientation relationship between them and silicon carbide which was epitaxially grown on silicon substrate during the carburization and bias treatment. It is suggested that the heteroepitaxial diamond can be obtained by the combination of the formation of silicon carbide, selective etching of silicon in silicon carbide network, filling the vacant silicon sites by carbonaceous ions, adding hydrocarbon radicals to the oriented $sp^3$-bond carbon clusters and etching non-diamond component and off-oriented $sp^3$-bond carbon clusters during the BEN process. The deposition and etching rates of the oriented diamond, the off-oriented diamond and the non-diamond component is very fast with respect to the deposition without bias since there are large quantities of carbonaceous species, accelerated ions and atomic hydrogen in the dense plasma. The increased amount of the etching rate by applied bias is larger than that of the deposition rate of the diamond. The strongly-bonded embryos with substrates due to ordered chemical bonds are relatively difficult to etch away while the weakly-bonded embryos are easily etched by atomic hydrogen to become gasified or unstable embryos of diamond. Consequently, the fraction of oriented embryos in total embryos formed on the surface is increased by preferential etching of off-oriented embryos. As a result, the oriented embryos are grown by adding the diamond precursor to the stable nuclei. Finally, highly oriented diamond film is formed after a growth step, while a few off-oriented embryos, which are survived after the bias step, grow to form azimuthally misoriented grains.

서지기타정보

서지기타정보
청구기호 {DMS 97008
형태사항 v, 164 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Yoon-Kee Kim
지도교수의 한글표기 : 이재영
지도교수의 영문표기 : Jai-Young Lee
학위논문 학위논문(박사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 157-164
주제 다이아몬드
헤테로에피텍시 성장
핵생성
음극바이어스
플라즈마 화학증착
Diamond
Heteroepitaxy growth
Nucleation
Negative bias
CVD plasma
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