鈣摻雜之非晶銅鋁氧化物薄膜特性分析

Properties of Amorphous Calcium-Doped Copper–Aluminum Oxide Thin Films

張弘(Hung Chang)

指導教授 ： 陳奕君

國立臺灣大學/電機資訊學院/光電工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.02341

摘要

銅鋁氧化物是深具應用潛力的p型透明導電材料。然而在低溫製程下獲得的銅鋁氧化物往往呈現非晶態，其電性不佳，故我們嘗試以摻雜Ca及調變薄膜的製程參數來增加其薄膜的導電性，以期得到更有使用價值的銅鋁氧化物薄膜。我們進一步利用此鈣摻雜之銅鋁氧化物與氧化鋅的結合成雙極性接面電晶體，並量測此元件特性及光學性質。
文中材利用射頻磁控濺鍍機搭配自製之銅鋁氧化物靶材沉積薄膜，並於靶材中摻雜Ca元素，以提升導電性，並在固定射頻功率100W、氬氣通量15sccm、工作壓力2mtorr下，改變氧氣分量及靶材成分，在室溫下沉積薄膜。並以XRD繞射儀檢測其結構為非結晶相，以四點量測量測獲取電阻率。以Ca0.2CuAl0.8O2靶材沉積之薄膜，在氧通量為10sccm下，有最佳之電阻率約為120Ω.cm，當薄膜厚度為700A時，其可見光(400~700nm)穿透率約為53%。SIMS成份分析中得知薄膜之Cu:Al約為2:1。低溫量測中發現其擁有熱激發型半導體之性質，在溫度低於190K時，有可變程跳躍的情況發生。
文中更進一步結合銅鋁氧化薄膜與氧他鋅薄膜，製作出AZO/ Ca0.2CuAl1.8O2/ ZnO雙極性接面電晶體主動元件，元件之β值約為1.1，而其可見光透光率約為64%。

關鍵字

銅鋁氧化物 ； 濺鍍 ； 非晶 ； 薄膜

並列摘要

Copper aluminum oxide is one interesting p-type transparent conducting oxide, which can be obtained by room-temperature sputtering. However, the as-deposited copper alumina oxide thin films are amorphous and have poor electrical propertied. Here, we try to doped the thin films with calcium to improve their electrical conductivity. We further made the bipolar junction transistors (BJT) by integrating copper aluminum oxide thin film with zinc oxide thin films, and the optical and electrical characteristics of the device were evaluated.
Thin films were sputtered from calcium doped copper aluminum oxide target at conditions of RF power = 100W, argon flow rate = 15sccm, and working pressure = 2mtorr. The oxygen flow rate and the target composition were varied. We used XRD to confirm that the thin films were amorphous. Their resistivity was obtained by four-point measurement. We found that thin film sputtered from Ca0.2CuAl0.8O2 target at oxygen flow rate of 10sccm had the lowest resistivity of 120Ω.cm.SIMS and EDS showed that the ratio of copper and aluminum was about 2:1. Low-temperature conductivity measurement indicated that there thin films were thermal-activation type semiconductor and variable-range hopping will occur under 190K.
The copper aluminum oxide thin films were futher integrated with zinc oxide thin films to form AZO/ Ca0.2CuAl1.8O2/ ZnO npn BJT, and find the β value of 1.1 and optical transmittance of 64% were obtained.

並列關鍵字

CuAlO2 ； Copper–Aluminum Oxide ； Amorphous ； sputter

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