鋁基電極鈦酸鍶鋇薄膜電容研製

Abstract

本研究使用射頻濺鍍方法在鋁基電極上備製鈦酸鍶鋇薄膜電容，實驗結果顯示在鋁基電極上備製鈦酸鍶鋇薄膜電容會導致很高的漏電流密度，然而雙層(非晶與結晶)結構可有效降低漏電流密度達兩個級數以上，達成良好的介電特性;漏電流密度在0.44MV/cm電場以下可維持於(10-7A/cm2)以下，介電常數可達(87.4)，本研究使用半導體參數分析儀HP4156進行漏電流密度－電場量測，以Keithley 595進行電容值－電壓量測，以XRD分析薄膜結晶性，以原子力顯微鏡掃描鈦酸鍶鋇薄膜表面形貌，以歐傑電子分析儀進行各層元素之縱深分析，以掃描式電子顯微鏡分析BST的厚度，以穿遂式電子顯微鏡進行電容橫截面結構分析。

Barium Strontium titanate thin films were deposited on Al-based electrodes by rf magnetron sputtering. Experimental results indicate that the BST film deposited on Al-based electrodes has a large leakage current density. However, it is found that the leakage current density can be reduced by two orders of magnitude using Multilayer (Amorphous and Crystal) BST film. Excellent electrical characteristics, including low leakage current density (10-7A/cm2) under 0.44M MV/cm, dielectric constant (87.4) can be achieved. The leakage current density versus dc electrical field was measured at 25。C using a HP4155A semiconductor parameter analyzer. The capacitance versus dc voltage (C-V) was measured at 1 MHz using Keithley 595.The dependence of the crystallinity of the different amorphous layer thickness was traced by XRD. An atomic force microscope (AFM) was used to characterize the surface morphology of the BST films. The depth profiles of BST and bottom electrode interface were analyzed by (AES). The BST films thickness were measured using a scanning electron microscope (SEM). The crystalline structure and the amorphous structure were analyzed using transmission electron microscopy (TEM)