- 學位論文
Oxidation Behavior of ZrN Thin Films in Vacuum and Nitrogen Enviroments
氮化鋯薄膜於真空及氮氣環境之氧化行為研究
摘要
在本研究中選擇熱處理的氣氛及溫度作為實驗設計變數，以探討氮化鋯薄膜在不同氣氛下的氧化作用。本研究係將氮化鋯薄膜鍍著在矽基材上，接著在真空及流動氮氣中分別進行四種不同溫度持溫一小時的熱處理，同時用氧偵測器監測系統的臨場氧分壓。利用置入試片與未置入試片時氧分壓的不同，計算出氧在氮化鋯薄膜中的溶解度，其結果顯示氧溶解入氮化鋯為一放熱反應，並由熱力學及動力學的角度計算討論氧化作用。從實驗結果發現，氮化鋯薄膜在真空及流動氮氣中熱處理後，不論在成分、結構及性質上皆有顯著的不同。氮化鋯薄膜在流動氮氣中熱處理後完全氧化，但經真空熱處理到了攝氏1000度以上才出現明顯的二氧化鋯相。在真空熱處理中，氧分壓隨著溫度上升從10-15上升到10-8大氣壓，可能是影響氧化的主要因素。在真空和氮氣熱處理中所形成的表面氧化層可能不同，因而導致不同的氧化行為。在氮氣中熱處理的試片表面上發現有空泡的出現，空泡的形成與破裂使得系統中的氧氣有更多的機會接觸到尚未氧化的氮化鋯，更加快了氧化反應。為了避免空泡的形成並得到較平坦的表面，氮化鋯在真空中熱處理是一個可行的方法。
並列摘要
The objective of this study is to understand the difference of the behaviors of ZrN thin film oxidation in different atmospheres. The annealing atmosphere and temperature were chosen to be the designate variables. In this study, ZrN thin film was deposited on Si substrate, and the samples were annealed in vacuum and flowing nitrogen respectively at four different temperatures for one hour. The oxygen partial pressure was monitored by a zirconia oxygen sensor during annealing. The solubility of oxygen in ZrN was calculated by comparing the difference of measured oxygen partial pressure between annealing with and without specimen. The dissolution of oxygen in ZrN is an exothermic reaction. The oxidation behavior was examined from thermodynamic and kinetic perspectives. Results indicated that the composition, structure and properties of the specimens annealed in vacuum and flowing nitrogen were completely different. All ZrN thin films were oxidized under annealing in flowing nitrogen. On the other hand, the specimens in vacuum annealing revealed substantial formation of ZrO2 at 1000°C and above. For vacuum annealing, it is observed that the oxygen partial pressure in the system, ranging from 10-15 to 10-8 atm, significantly varied with temperature from 800 to 1100 °C, which is the main factor leading to oxidation. The surface oxide layer formed in vacuum annealing may be different from that in nitrogen gas, and thereby affecting oxidation behavior. Blisters were observed on the surface for the samples annealed in nitrogen. Once the blisters formed, more oxygen could penetrate the thin film through the cracked blisters and the ZrN film would be oxidized rapidly. To avoid blister formation and maintain a smoother surface, heat treatment of ZrN in vacuum was a feasible method.