In this experimental work, a p-type c-Si (100) substrate with 8 × 8 × 2 mm dimension was taken for TiCN thin-film coating deposition. The whole deposition process was carried out by chemical vapor deposition (CVD) process. The Si substrate was placed within the CVD chamber at base pressure and process pressure of 0.75 and 500 mTorr, respectively, in the presence of TiO2 (99.99% pure) and C (99.99% pure) powder mixture. Later on, quantity of C powder was varied for different set experiments. The deposition of TiCN coating was carried out in the presence of N2– H2–TiCl4–CH3CN gas mixture and 600 ℃ of fixed temperature. The time for deposition was fixed for 90 min with 10 and 5 ℃ min− 1 heating and cooling rate, respectively. Later on, heat treatment process was carried out over these deposited TiCN samples to investigate the changing characteristics. The heat treatment was carried out at 800 ℃ within the CVD chamber in the absence of any gas flow rate. The morphological properties of heat-treated samples have been improved significantly, evidence is observed from SEM and AFM analyses. The structural analysis by XRD has been suggested, upgradation in crystallinity of the heat-treated film as it possessed with sharp and higher intensity peaks. Evidence has been found that the electrochemical properties are enhanced for heat-treated sample. Raman spectroscopy shows that the intensity of acoustic phonon modes predominates the optic phonon modes for untreated samples, whereas for heat-treated samples, opposite trends have been observed. However, significant degradation in mechanical properties for heat-treated sample has been observed compared to untreated sample.
The deposition process for the gap-filling of sub-micrometer trenches using DMDMOS, (CH3)2Si(OCH3)2, and CxHyOz by flowable chemical vapor deposition (F-CVD) is presented. We obtained low-k films that possess superior gap-filling properties on trench patterns without voids or delamination. The newly developed technique for the gap-filling of submicrometer features will have a great impact on IMD and STI for the next generation of microelectronic devices. Moreover, this bottom up gap-fill mode is expected to be universal in other chemical vapor deposition systems.
Taguchi methodology has been applied to get an idea about the parameters related to the chemical vapour deposition technique, which influences the formation of semiconducting carbon thin film of a desired band gap. L9 orthogonal array was used for this purpose. The analysis based on Taguchi methodology suggests that amongst the parameters selected, the temperature of pyrolysis significantly controls the magnitude of band gap (46%). Sintering time has a small influence (30%) on the band gap formation and other factors have almost no influence on the band gap formation. Moreover this analysis suggests that lower temperature of pyrolysis (≤ 750℃) and lower time of sintering (≤ 1 h) should be preferred to get carbon thin film with the desired band gap of 1.2eV.
Ta(TaC) 필라멘트를 이용한 HF-CVD 법에 의하여 Si3N4, SiC, WC, Al2O3를 기판으로 다이아몬드 박막을 증착하고, 그 밀착특성을 평가하였다. 로내의 CH4농도를 10%로 높게 하였을 경우에는 막중에 graphitic(amorphous) carbon이 생성됨을 확인할 수 있었다. 박막을 12μm 정도까지 두껍게 하면, WC기판에서는 부분적 박리형상이 관찰되었으나, Si3N4를 기판으로 하였을 경우에는 안정한 박막을 얻을 수 있었다. Indentation test 결과로부터 grainding에 의한 기판표 처리가 밀착성 향상에 효과적이라는 것을 알 수 있었다. 또 compression topple test에서는 박막의 두께는 밀착성과 반비례의 관계를 가지는 것을 알 수 있었다. 수 있었다.
다이아몬드 증착시 기판의 표면처리를 변화시켰을 때 다이아몬드의 핵생성 밀도에 미치는 영향에 대하여 연구하였다. 실험장치는 열 필라멘트 CVD 장치를 사용하였고, 반응가스로 메탄과 수소가스를 사용하였다. 기판의 표면 처리는 탄소 상을 기판에 증착시키는 방법, Soot에 의한 기판 표면처리, 혹연에 의한 기판 표면처리로 크게 3가지로 행하였다. 모든 경우에 핵생성 밀도가 증가하였으나 탄소 상을 증착시킨 경우와 soot에 의한 사전처리의 경우의 핵생성 밀도의 증가가 혹연에 의한 처리보다 더 현저하였다. 또한 탄소강의 증착의 경우 표면에 굴곡이 없는 매우 평탄하고 균일한 다이아몬드 막을 얻을 수 있었다. 사전증착처리 한 기판에 탄소 층을 형성시켰을 때 탄소 층과 기판과의 접착력이 약한 것을 이용하여 다이아몬드 막을 쉽게 분리시켜 free standing 다이아몬드 박막을 얻을 수 있음을 알았다.