本文選題：改進(jìn)型MPCVD裝置 + 均勻性��； 參考：《武漢工程大學(xué)》2015年碩士論文

【摘要】：金剛石擁有優(yōu)異的物理化學(xué)性質(zhì),因而作為新型材料具有極其廣闊的發(fā)展前景。化學(xué)氣相沉積法(Chemical vapor deposition,CVD)作為成膜質(zhì)量性能堪比天然金剛石的優(yōu)良特性受到了各領(lǐng)域的廣泛關(guān)注。在諸多方式中,微波等離子體化學(xué)氣相沉積法(Microwave Plasma Chemical Vapor Deposition,MPCVD)因其獨特的無極放電低污染模式、等離子體能量高度集中等優(yōu)勢成為高質(zhì)量大面積金剛石膜沉積時的最佳選擇。目前國內(nèi)金剛石膜沉積方面的研究,主要受到大面積MPCVD沉積設(shè)備及相關(guān)工藝參數(shù)的系統(tǒng)研究所限,在此領(lǐng)域獲得突破較少。本論文利用實驗室自制的10kW MPCVD裝置,系統(tǒng)研究各項工藝參數(shù)對薄膜沉積質(zhì)量、均勻性等指標(biāo)的相關(guān)影響,并根據(jù)所獲得結(jié)果對裝置結(jié)構(gòu)、實際最佳工藝參數(shù)進(jìn)行改進(jìn)和總結(jié),為高質(zhì)量大面積金剛石膜的實用化提供了實驗依據(jù)。在本次研究過程,首先對各項工藝參數(shù)進(jìn)行了綜合研究,通過對比不同微波功率、沉積氣壓下基片的溫度,確認(rèn)了改進(jìn)型裝置對均勻成膜的有力幫助,同時掌握微波功率與氣壓對基片溫度、等離子體均勻性的影響關(guān)系;并以此為基礎(chǔ)比較不同甲烷濃度與微波功率下金剛石膜的沉積速率,結(jié)果表明提高甲烷濃度與微波輸出功率均能有效地提升金剛石膜的沉積速率,且在甲烷濃度超過1%、基片溫度超過850℃處存在明顯轉(zhuǎn)折點。通過歸納實驗所得數(shù)據(jù)總結(jié)出最佳工藝參數(shù),并成功制備了均勻性較好的直徑達(dá)到100mm的大面積金剛石膜。其次,通過對比實驗初步地研究引入輔助氣體對金剛石膜沉積過程的影響。實驗結(jié)果表明在所選工藝參數(shù)下引入少量氧氣可以使金剛石膜的質(zhì)量大幅提高,同時沉積速率與取向性都有所提高;引入少量二氧化碳可顯著提高薄膜的沉積速率,但表面均勻性明顯受到影響;而引入少量氮氣則會抑制晶粒生長并顯著促進(jìn)二次形核。最后系統(tǒng)地研究不同濃度混合比的氮氧混合氣體對金剛石膜生長的影響,發(fā)現(xiàn)氮氧混合氣體對金剛石膜生長的影響主要由其中濃度較高的組分決定,即氮氣濃度較高時主要表現(xiàn)出抑制生長與促進(jìn)二次形核,而氧氣濃度較高時主要表現(xiàn)為提高成膜質(zhì)量與取向性;在此基礎(chǔ)上嘗試?yán)脤嶒炈@得的結(jié)果進(jìn)行薄膜制備,在適當(dāng)?shù)墓に噮?shù)下成功獲得了有一定均勻性的大面積納米金剛石膜。嘗試性使用四探針方塊電阻測試儀,對所得納米級金剛石膜均勻性進(jìn)行了定性檢測,并發(fā)現(xiàn)測定結(jié)果準(zhǔn)確性易受基片條件、結(jié)合程度與薄膜沉積厚度的影響。
[Abstract]:Diamond has excellent physical and chemical properties, so it has a broad development prospect as a new material. Chemical vapor deposition (CVD) as a film forming quality property comparable to the excellent properties of natural diamond has received extensive attention in various fields. In many ways, microwave plasma chemical vapor deposition (MPCVD) is the best choice for high quality and large area diamond film deposition due to its unique low pollution mode of electrodeless discharge and high concentration of plasma energy. At present, the research on diamond film deposition in China is mainly limited by the systematic research of the large area MPCVD deposition equipment and related technological parameters, but there are few breakthroughs in this field. In this paper, a 10kW MPCVD device made by the laboratory is used to systematically study the influence of various technological parameters on the quality and uniformity of the film deposition. According to the obtained results, the structure of the device and the practical optimum process parameters are improved and summarized. It provides experimental basis for the practical application of high quality large area diamond films. In this research process, various technological parameters are studied comprehensively. By comparing different microwave power and temperature of substrate under deposition pressure, it is confirmed that the improved device has the force to help uniform film formation. The effects of microwave power and pressure on substrate temperature and plasma homogeneity were studied, and the deposition rates of diamond films with different methane concentrations and microwave power were compared. The results show that both methane concentration and microwave output power can effectively increase the deposition rate of diamond films, and there is an obvious turning point when methane concentration exceeds 1 and substrate temperature exceeds 850 鈩，

本文編號：2095399