本研究乃以四甲基矽烷（TMS）、氨氣、氫氣為原料氣體的內熱式低壓化學氣相沈積系統，藉由碳化矽/氮化矽複合膜沉積於石墨基材上，作為石墨與碳化矽覆膜間的熱應力緩和傾斜層。利用在氫氣氣氛下控制原料TMS對NH3供給的分壓比(PTMS/NH3)，調整複合層中Si-C/Si-N鍵結的比例，隨著PTMS/NH3分壓比由0.75到24的上升對應出薄膜中Si-C/Si-N比例可由0.9上升至6，又其所對應的理論熱膨脹係數可由4.2改變至4.87。由實驗結果得知當反應溫度1000℃，PTMS/NH3 = 3時所製備出的碳化矽/氮化矽複合膜與石墨基材在熱性質上十分接近，此時藉由1000~1165℃的溫度控制亦可對應到Si-C/Si-N 由 2.3~3.7的變化特性，來製備出一系列Si-C/Si-N組成比不同的複合膜傾斜層(gradient layer)，以緩和石墨與碳化矽覆膜因熱膨脹係數不整合在升降溫所產生的熱應力。最後發現石墨基材再經TMS分壓14.6 × 10-2 Torr、氨氣添加量0.5sccm、反應溫度700℃、滲透時間55分鐘的CVI法處理，加上厚度約為2.8μm的複合膜傾斜層，及最上一層5 μm厚的SiC覆膜樣品。在空氣下可達到16個熱測試循環後（1000℃），重量損失在3%以下。又在氨氣氣氛下，經過220個熱穩定測試循環（1200℃）後，發現並沒有任何明顯重量損失，且在光學顯微鏡下觀察表面形態，只發現少數且細微的裂縫產生。

The purpose of this research is to grow silicon carbide/silicon nitride composite films using TMS (tetramethylsilane), ammonia and hydrogen as the reactant gases by chemical vapor deposition. The reactant feed ratio of TMS/NH3 were varied from 0.75 to 24,the composition ratio of Si-C/S-N in the films were increasing from 0.9 to 6, the corresponding theoretical thermal expansion coefficient of films were varied from 4.6 to 4.75. It was found that this first gradient layer was familiar with graphite substrate at 1000℃ and PTMSNH3 = 3. When temperature in the range of 1000 to 1165℃ to fabricate other serial gradient layers. Then, the substrate treated with the CVI process at 700℃, TMS partial pressure of 14.6 × 10-2 Torr NH3 = 0.5sccm and reaction time = 55min. The gardinet layer (2.8μm) is grow on graphite. Finally, grow thickness 5μm on top layer. This process makes the weight loss of sample below 3% under the 16 cycles of thermal shock test in air atmosphere (1000℃). After 220 cycles of thermal shock test in ammonia atmosphere (1200℃), there were a few cracks in SiC coating film observed by optical microscope and the weight loss was unapparent.

參考文獻：
[1] 袁澄波,石作岷,陳汝翼,“石墨材料之開發利用”,漢復出版社,pp.1-10(1998)。
[2] D.G. Godtrey, Met. Mater. 2, 305 (1968).
[3] J.E. Sheesan and J.R. Strife, J. AM. Ceram. Bull, 67, 369 (1988).
[4] A.A. Anari etal, Mater. Sci. Eng., 88, 55 (1988).
[5] G. Savage, Carbon-carbon compositions., Chapman and Hall, p.208 (1992).
[6] Bickerdike RL, Brown ARG, Hughes G, Ranson H. Proc. 5th Conf. on Carbon. New York: Pergamon Press; 1962. p. 575.
[7] R.L Beatty, J. Nucl. Appl. Technol. 8, 488 (1970).
[8] Starr TL. Cream Eng Sci Proc 1988;9:803.
[9] K. Sugiyama and Y. Ohzawa, J. Mater. Sci. Lett. 25, 4511 (1990).
[10] P. Dupel, X. Bourrat and R. Pailler, Carbon, 33, 1193 (1995).
[11] K.A. Appiah, Z.L. Wang, W.J. Lackey, Thin solid films, 371, 114 (2000).
[12] Y. G. Jung, S. W. Park and S. C. Choi, Materials Letters, 30, 339 (1997).
[13] Y. Kim, J. T. Choi, J. K. Choi and K. H. Auh, Materials Letters, 26, 249 (1996).
[14] D. C. Jia, Y. Zhou and T. C. Lei, Ceramics International, 22 107 (1996).
[15] K. Kanai and M. Fukagawa, JR Patent, P2000-302576A, (1996).
[16] H. Kurai and T. Mashui, JR Patent, H8-133877, (1996).
[17] K. Nozawa and M. Nakajima, JR Patent, H3-146672, (1991).
[18] 張義貴，“以四甲基矽烷為先驅物氣相沉積碳化矽膜作為石墨保護層的研究”，國立台灣科技大學，碩士論文(2004)。
[19] 李芳中，“以化學氣相沉積法合成韌性複合材料碳化矽/氮化矽之研究”，國立台灣科技大學，碩士論文(1999)。
[20] 潘鼎翔，“光學薄膜應力量測與分析之探討”，國立中央大學，碩士論文(2003)。
[21] 莊達人，VLSI製造技術，高立圖書(2002)。
[22] S Scaglione, D Flori and L Caneve, Pure Appl. Opt.3 491-496(1994).