LSCO/AZO 異質接面製備與特性之研究

STUDIES ON THE PREPARATION AND CHARACTERIZATION OF LSCO/AZO HETEROJUNCTIONS

李鑫(Shin Lee)

指導教授 ： 胡毅

大同大學/工程學院/材料工程學系所/博士(2012年)

摘要

本研究利用射頻磁控濺鍍（radio frequency（R. F.）magnetron sputtering）技術在矽基板上製備出Al-doped ZnO（AZO）/La1-XSrXCoO3（LSCO）之氧化物異質接面二極體。先將AZO薄膜沈積在矽基板上，並將AZO薄膜置於氬氣氣氛下做退火熱處理，再將LSCO薄膜沈積在已熱處理過之AZO薄膜上即可製備出本次研究之AZO/LSCO異質結構。製備出之異質接面在電流-電壓曲線（I-V curve）的關係上表現出非對稱之關係，且在反向偏壓時擁有良好的整流特性（rectifying property）。二極體在AZO薄膜退火溫度為500℃時有最佳之整流特性，其I-V curve斜率大約為0.25 mA/V。經I-V curve之推算，異質接面之開路電壓約為1.6 V且不會隨著AZO薄膜退火溫度的改變而改變。在沈積LSCO薄膜時氬氣氧氣比例為10:5（sccm）之二極體有最佳之整流特性，其I-V curve斜率大約為0.31 mA/V。經I-V curve之推算，異質接面之開路電壓亦約為1.6 V且不會隨著沈積LSCO薄膜時氬氣氬氣比例的改變而改變。異質接面二極體之開路電壓約為1.6 V與藉由LSCO及AZO薄膜之功函數得到之結果相一致，異質接面之能帶圖亦利用分析之數據繪得。

關鍵字

氧化鋅鋁 ； 濺鍍 ； 鈷酸鑭鍶 ； 異質接面

並列摘要

Oxide heterojunction diodes with La1-XSrXCoO3 (LSCO) and n-type Al-doped ZnO (AZO) thin films on Si substrate were fabricated by radio frequency (R. F.) magnetron sputtering technology. The AZO thin film was first deposited on the Si substrate and annealed in an argon atmosphere. The heterostructure was obtained by stacking the LSCO thin film on the annealed AZO thin film without annealing. The AZO/LSCO diode exhibited an asymmetric current-voltage relationship with a reverse shape of a good rectifying property. The diode with an AZO thin film annealed at 500 °C exhibited the maximum forward-to-reverse current ratio of about 0.25 mA/V. The turn-on voltage of the diode was about 1.6 V and was found to be independent of the annealing temperature of the AZO thin film. The diode with an LSCO thin film deposited at Ar:O2 sputter gas ratio was 10:5 (sccm) exhibited the maximum forward-to-reverse current ratio of about 0.31 mA/V. The turn-on voltage of the diode was about 1.6 V and was found to be independent of the deposited Ar:O2 sputter gas ratio of the LSCO thin film. The turn-on voltage of the diodes is obtained around 1.6 V and is in agreement with the value obtained from the difference in the work functions of LSCO and AZO. The band structure of the heterojunction was proposed based on the analyzed results.

並列關鍵字

sputter ； AZO ； heterojunctions ； LSCO

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