鈀/鐵與鐵/鈀雙層膜於矽基板(111)上 熱穩定性與合金形成之研究

Abstract

本篇論文為探討在壓力1.6×〖10〗^(-9) torr的室溫下，於清理過的矽基板上鍍上不同厚度與相對位置之鈀與鐵雙層膜的熱穩定性與合金形成。為了觀察從分離的雙層膜到合金的轉變過程，我們已經研究了退火時間與溫度的效應，藉由歐傑電子能譜(AES)的測量，在歐傑電子能譜圖中觀察到相分離。溫度在大約690至804 K之間，Pd/Si與Fe/Si歐傑訊號比值呈現了兩種不同的下降過程，前者比後者下降的更為急遽。下降的Pd/Si與Fe/Si訊號比值表示在不同相對位置的兩雙層膜系統中，Pd與Fe原子會擴散到矽基板裡。Fe/Pd與Pd/Fe曲線在兩種系統中也被發現有相似的趨勢，在相對高溫情況下，Fe/Pd與Pd/Fe曲線相交後，Fe/Pd訊號比值將會大於Pd/Fe訊號比值。我們的研究提供了在矽基板(111)上的鈀與鐵雙層膜之熱穩定性與合金形成之詳細報告，這些報告在未來的應用上是有價值的。

The bilayers of Pd and Fe with different thicknesses and relative positions were grown on the flashed Si (111) surface at room temperature in an ultrahigh vacuum with a base pressure of 1.6 × 10¯⁹ torr. In order to observe the transformation processes from the separated bilayers into alloys, the annealing-time and annealing-temperature effects were investigated. By Auger electron spectroscopy (AES), the phase separations were found in Auger diagrams. At the temperature of about 690-804 K, two kinds of decreasing processes were observed in the Auger signal ratios of Pd/Si and Fe/Si. The fore process was steeper than later one. The decreasing ratios of Pd/Si and Fe/Si indicated the Pd and Fe atoms diffuse into the Si substrate in both systems of bilayers with different relative positions. The similar tendencies of Fe/Pd and Pd/Fe curves were also found in both systems. At relative high temperature, the Fe/Pd and Pd/Fe curves crossed at different thickness of iron layer, respectively. Our study provides detailed information about the thermal stability and the alloy formation in Pd-Fe bilayers on Si(111), which will be valuable in future applications.