RF磁控濺鍍製程參數對AZO透明導電膜性質的影響

Influence of fabrication parameters on the performance of AZO films grown by RF magnetron sputtering

蔡曉寬(Hsiao-Kuan Tsai)

指導教授 ： 楊木榮

大同大學/工程學院/材料工程學系所/碩士(2006年)

摘要

成功利用自組裝的濺鍍系統以自製之3wt%氧化鋁摻雜的氧化鋅靶材製作AZO透明導電膜於Schott B270光學玻璃基板上，本研究將著重於不同電漿製程參數對於AZO透明導電膜物理性質表現之研究，所探討的電漿製程參數有: 鍍膜時間(T)、工作壓力(Wp)、RF濺鍍功率(PRF)及靶材至基板距離(Dts)。各參數所製得的AZO透明導電膜經XRD結構分析得其結構為具有(002)擇優取向的Wurtzite結構，由光學分析可知，氧化鋅為一直接能隙的半導體材料，並且隨著載子濃度的提升而會造成其光學能隙會有藍移的現象，此即著名的Burstein-Moss effect。並且從鍍膜時間變化的實驗中，可獲知此濺鍍製程為一穩定的製程，在工作壓力10mTorr、RF濺鍍功率120W、靶材至基材距離10cm下，其成膜速率為2.7nm/min。由實驗結果，可獲知愈大的RF濺鍍功率可獲得較低的電阻率，在本研究中，在製程參數T=60mins、Wp=2mTorr、PRF=120W、Dts=7cm下可獲得膜厚為335nm最佳性質的AZO透明導電膜，其可見光透光率大約85%及電阻率為5.75×10-4Ωcm(片電阻~17Ω/□)。

關鍵字

氧化鋅透明導電膜 ； RF磁控濺鍍

並列摘要

Al-doped zinc oxide (AZO) films on Schott B270 glass substrates are successfully prepared by homemade RF magnetron sputtering system with a 3wt% Al2O3 doped zinc oxide target. The effects of different deposition parameters on the physical properties of AZO films were studied. The parameters include the deposition duration (T), working pressure (Wp), RF sputtering power (PRF), and target-to-substrate gap (Dts). All AZO films prepared by RF sputtering are crystalline with (002) crystallographic orientation of wurtzite structure. From the results of deposition under various durations, the deposition rate is about 2.7nm/min for RF plasma sputtering under the power of 120W. The linear relationship between the film thickness and deposition time also indicates the sputtering process is stable process. For the parameters of the working pressure, sputtering power, and target-to-substrate gap (Dts), the results seemingly indicate that the higher energy input (or density) during sputtering will get to a film with lower resistance. In this study, the film with thickness of 335nm, prepared under T=60mins, Wp=2mTorr, PRF=120W, and Dts=7cm, exhibits the lowest resistivity of 5.75×10-4Ωcm(~17Ω/□) and the transmittance of 85%. From the results of the optical spectra, the optical energy gap of AZO films with direct band gap semiconductor materials can be determined. While more Al atoms act as dopant atoms in AZO films, the conductivity of AZO films is increasing due to the increase of the carrier concentration. Furthermore, the increase in carrier concentration causes optical band gap blue shift. This is well-known Burstein-Moss effect.

並列關鍵字

AZO films ； RF magnetron sputtering ； Burstein-Moss effect

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