本研究使用金屬鈦(Ti)及氧化釔(Y2O3)做為濺鍍源，利用磁控濺
鍍製程，在矽基板上成長氧化釔及氧化鈦單層成分分佈薄膜，以及氧
化釔-氧化鈦成分分佈薄膜系統，最後以金屬鉭做為金屬閘極，形成
金屬/介電層/半導體(MOS)電容結構，並在還原性氣體下對成分分佈
薄膜進行退火熱處理(3500C)。探討氧化釔-氧化鈦成分分佈薄膜作為
高介電應用之電性行為及物理性質以及參雜氮之影響。
實驗結果顯示在此製程中獲得品質好的氧化釔-氧化鈦成分分佈
薄膜系統並藉此推算薄膜系統的成分變化;由於釔擴散與二氧化矽反
應成矽酸釔(yttrium silicate) 的緣故，中介層厚度從富含鈦的區
域到富含釔的區域逐漸增加，即從1.1 變化到2.7nm。從薄膜系統介
電層厚度變化中可看出均勻性高;在電性方面，結果顯示在氧化釔-
氧化鈦成分分佈薄膜系統中，當氧化鈦比例小於40%時，介電常數可
提高到約40，且此時漏電流密度約為10-5 A/cm2 。研究指出參雜氮可
減少位於介電層氧空位數量，且預防氧擴散到中介層，可改善元件性
能。在參雜氮後，介電性質從40%TiO2 改善至70%TiO2 且降低漏電流
一到兩個級數。

Y2O3-TiO2 composition spreads are prepared by reactive magnetron sputtering from Y2O3 and Ti targets, following by a forming gas annealing at 350 C. We have discussed the physical and electrical characteristics of the Y2O3-TiO2 composition spreads for the high-k application.
Second ion mass spectrometry (SIMS) and EDX (built in SEM) were utilized to determine the quality and compositions of the Y2O3-TiO2 composition spreads. High-resolution transmission electron microscopy (HRTEM) images were used to analyze the microstructures, including the thicknesses of oxide layers and interfacial layers. The crystallinity was
confirmed by select area electron diffraction (SAED) patterns. The thicknesses of the interfacial layers gradually increase from Ti-rich to Y-rich, namely from  1.1 nm to  2.7 nm, due to more yttrium diffusion.From the C-V/I-V measurements, we found some devices with reasonably low leakage current density (10-5 A/cm2), whose dielectric
constants could be tuned up to around 40 when concentration of TiO2 was ~ 40 % for Y2O3-TiO2 composition spreads.
In addition, N2-doped was studied as well. After N2 doping, the C-V characteristics could be enhanced up to 70 % of TiO2. Averagely the leakage current density was around one to two orders lower, compared to the composition spread without N2 doped.

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