溶膠-凝膠法製備二氧化鋯薄膜之物性和電性研究

Abstract

根據全球半導體技術藍圖的評估，未來高介電材料將是應用在下一世代超大型積體電路優先選擇的候選絕緣層，為了滿足以上的需求並獲得較低的漏電流及可靠度，利用高介電材料來取代二氧化矽以及後續的處理變成不可或缺的 一般傳統高介電薄膜是以原子層沈積法和物理氣象沈積法來製備的，但是上述的沈積方法仍然存在著許多複雜的問題，例如是薄膜的均勻度和備製的成本，近來，以溶膠-凝膠法來備製薄膜的技術便的越來越受矚目，當前驅物的金屬鹵化物會與溶劑在特定的條件下產生水解現象，溶膠-凝膠法其溶液包含膠狀態的溶劑或是前驅物的混合物，對於製程來說溶膠-凝膠法是一種簡單、快速且低成本的方法。 在這篇論文中，我們將研究以溶膠-凝膠法用四氯化鋯當前驅物來備置二氧化鋯薄膜，先將前驅物四氯化鋯粉末溶解在兩種方式混合的溶劑中-異丙醇+己醇、正辛醇，由上述兩種方式混合的溶液以溶膠-凝膠法在矽基板上沉積二氧化鋯薄膜，在增益二氧化鋯薄膜其本身的物性和電特性扮演著相當重要的角色，研究發現退火條件對於二氧化鋯在物性和電性方面有非常大的影響，經過退火後的二氧化鋯薄膜其本身的電性將會被增益且是極佳的電絕緣體，然後我們去比較上述兩種溶膠-凝膠方式所沈積二氧化鋯薄膜的基本物性和電性，在各方面其特性幾乎是非常相近的，但是，由四氯化鋯直接溶解在正辛醇溶劑所得到的溶膠-凝膠法所配製出二氧化鋯薄膜其本身的介電常數較高，由溶膠–凝膠法所得到的二氧化鋯薄膜是非常受期待應用在電容器或是電絕緣層，對於這篇研究以溶膠–凝膠法來製備二氧化鋯薄膜的方式是相當令人滿意的。

According to International Technology Roadmap for Semiconductor, the high-k dielectric materials will be excellent candidates for future ultra-large-scale-integration (ULSI) application. To meet the above requirements and exhibit a low leakage and a good reliability, the replacements of high dielectric constant materials for the silicon dioxide and additional treatment have become indispensable. Traditional high-k thin films have been prepared by atomic layer deposition (ALD) and physical vapor deposition (PVD). But those methods have involved several problems, such as the uniformity of the thin films and the preparation cost. Recently, sol-gel method has been a great interest as a new technique to prepare thin films. Sol-gel method can obtain colloidal solvent or precursor compound when the metal halides are hydrolyzed under controlled conditions. It is a simple, rapid, and low cost method. In this thesis, ZrO2 thin films are prepared by sol-gel method using metal halides (ZrCl4). The precursor of ZrCl4 powder is dissolved in two kinds of mixing solvent IPA + Hexanol and 1-Octanol. Sol-gel-derived ZrO2 films on Si substrate are forming using two different mixing solvent. The physical characterization and electrical properties play important roles in governing the physicochemical properties as well as the performance of ZrO2. Annealed conditions have shown to greatly influence the physical and electrical properties of ZrO2. After annealing, the electrical performances of sol-gel-derived ZrO2 thin films show good electrical insulation. Then, we compare with the physical and electrical properties of two forming methods, ZrCl4 + Octanol has similar characteristics to ZrCl4 + IPA + Hexanol derived films. But the ZrCl4 + Octanol sol-gel-derived dielectric film has higher dielectric constant than ZrCl4 + IPA + Hexanol. Sol-gel-derived ZrO2 thin film is expected as the capacitor and coating for insulating film. Sol-gel method is used for preparing ZrO2 films to satisfy for study.