本實驗室使用分子束磊晶的方法成長HfO2 高介電常數氧化層在矽晶片上。經由RHEED及TEM的分析，HfO2/Si之間並無任何的二氧化矽或其它的矽氧化物產生。這是在此領域第一次發現的成果。除此之外，我們利用氮氣的環境中濺鍍鈦的方式獲得TiN當做金屬閘極，並且在TiN上面再鍍上純金屬鈦以增加熱穩定性。此Ti/TiN雙層結構在溫度達850oC時仍不會有破裂現象發生，電阻值也隨著溫度升高而降低，這兩項發現皆有利於後續的電晶體製程。利用上述材料所製作的電容元件熱穩定度特性也將在本論文中探討，我們發現元件經過850oC退火後，漏電流密度比未退火的元件高八個數量級，主要的原因是HfO2的再結晶現象。然而此數值仍比相同等效厚度的二氧化矽所製作的元件低。在另一方面，元件經過700oC退火後及保有良好的電容特性，但當溫度達850oC時有衰退的現象。此結構所得到的最低等效厚度為1.53nm。界面間的能量態密度經Terman method方法計算約為1012 到1013 ev-1cm-2之間，並且當退火溫度由600oC升至700oC時有增加的趨勢，由700oC升至800oC時卻是下降的趨勢。在電晶體的製作方面，經由lift-off 的方法我們成功地整合了所有的製程並克服機台與試片尺寸的限制。所製做出的self-aligned電晶體也有合理的電性結果，並且在退火溫度700oC時得到了最佳的互導(transconductance) 約48.5ms/mm.

In this MS thesis, we employed the molecular beam epitaxy (MBE) method to deposit amorphous HfO2 dielectrics (k = 15) on silicon. Based on extensive characterizations including RHEED and TEM, we have demonstrated for the first time an atomically abrupt HfO2/Si interface free of SiO2 or silicate formation. In addition, TiN electrode was deposited by reactive sputtering from a pure Ti target in Ar/N2 plasma. To improve the thermal stability of the films, pure titanium metal was deposited to form the capping layer and we found that almost no crack on the film surface when samples were subjected to high temperature annealing (~850oC). The resistivity of Ti/TiN was decreased when increasing the temperature. Furthermore, the thermal stability of high-k gate dielectric MOS capacitors with Ti/TiN as the metal gate (Ti/TiN/HfO2/Si) was studied. We found the leakage current densities of samples after annealing at 850oC was eight orders of magnitude larger than that of as deposited samples, which may result from the recrystallization of HfO2 film. However, all the samples showed lower leakage current densities compared to that of SiO2 at the same EOT. On the other hand, we found the capacitors showed good performance even though the temperature was up to 700oC, but a degradation in electrical characteristics at 850oC. The lowest EOT achieved for this structure was 1.53 nm. Moreover, the Dit of the sample increased when the temperature was raised from 600oC to 700oC, but it decreased when the temperature was further increased to 800oC. The value of Dit was ranging from 1012 to 1013 ev-1cm-2. For MOSFET process, a simple fabrication steps using lift-off process were established. The reasonable electrical characteristics of the MOSFET have been performed and the best transconductance, about 48.5mS/mm, was obtained when the activate temperature was at 700oC.

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