高介電常數材料二氧化鉿於金屬-絕緣體-金屬電容之研究

Abstract

摘 要

對於金絕金電容而言，尺寸的微縮可以減少晶片的大小和類比與射頻電路的成本。為了達到高電容密度與低漏電流密度的目標，高介電係數材料的需求是必要的。金絕金電容是利用濺鍍二氧化鉿和鉭組成。使用二氧化鉿當高介電係數材料的金絕金電容，電容密度高達25.67fF/um2 以及漏電流密度大約3.5×10-7 A/cm2。 之後，我們討論沉積後退火對於金絕金電容的影響。發現到元件的漏電流密度在做完通氧氣時沉積後退火會變小，電容密度則是再作完通氮氣時沉積後退火會變大的結果。另外，我們還討論表面電漿處理對金絕金電容的影響。發現到元件的電容電壓係數會變小的特性。

Abstract

Continuous down-scaling of the size of metal–insulator–metal (MIM) capacitors is required to reduce chip size and the cost of analog and RF ICs. The use of a high-k dielectric is the only way to achieve this goal, since decreasing the dielectric thickness to achieve high capacitance density degrades the leakage current. Metal-insulator- metal (MIM) capacitors are fabricated using sputtered HfO2 with Ta for top and bottom electrodes. A very high density of 25.67fF/um2 has been measured in metal–insulator–metal (MIM) capacitors which use high-k HfO2 the dielectric. The characteristics the MIM capacitors show the leakage current densities around 3.5×10-7 A/ cm2