以濺鍍法沉積矽摻雜氮化鋁薄膜之電特性研究

The electrical properties of Si-doped AlN thin film by using Helicon sputtering method

張書瀚(Shu-Han Chang)

指導教授 ： 高慧玲

中原大學/工學院/電子工程研究所/碩士(2014年)

https://doi.org/10.6840/cycu201400641

摘要

近年來對寬能隙半導體研究十分熱絡，其寬能隙之特性可應用於深紫外光發射或感測元件。其中，AlN直接能隙高達6.2eV，同時具有良好化學與熱穩定性、熱導性、抗輻射性等優點，使之適合應用於深紫外光電元件、高功率元件等，為了使AlN薄膜能更進一步應用於元件中，必頇將摻質有效地摻入薄膜中，用以提高薄膜之導電性，達成理想AlN之p-n接面。
本研究使用迴旋濺鍍系統於sapphire基板上進行c軸從優取向之AlN磊晶薄膜沉積；同時以Al-Si接合靶於AlN薄膜進行沉積時將Si原子摻入，經由二次離子質譜儀之縱身濃度分佈量測證實，藉由調整Si 靶材直徑可以控制摻雜濃度。在電性量測方面，使用Al金屬作為Si 摻雜AlN薄膜之接觸電極，並於TLM量測架構下測得特徵電阻值約為10^7~10^8 ohm-cm^2。由於Si摻雜AlN 薄膜呈現高阻值特性，所以無法使用一般Van der pauw模式進行薄膜電阻率與霍爾量測；因此將Si摻雜AlN薄膜製作成MESA形式，同時搭配特殊Hall bar電極設計，完成高阻值之四點電性量測架構。最後以Keithley 6487電壓源與Keithley 182伏特計，並於高阻值之四點量測下進行量測；當Si 摻雜濃度約為10^20 cm^-3 時，Si摻雜AlN薄膜之電阻率為3.3×10^6 ohm-cm，電子濃度為3.1×10^11 cm^-3，遷移率為6.1 cm^-2/V-s。

關鍵字

濺鍍 ； 寬能隙 ； 遷移率 ； 電阻率 ； Si摻雜 ； AlN

並列摘要

Recently, the research of the wide band gap semiconductor is very popular.The wide band gap characteristics of the materials can be applied to deep ultraviolet (UV) LED and detectors. With the widest band gap of 6.2eV among III-Nitrides, AlN also has many merits including the chemical and thermal stability, high thermal conductivity, and anti-radiation characteristics, making it suitable for the development of deep UV and high power devices. In order to broaden the scope of applications, it’s necessary to investigate the doping efficiency of Si in AlN thin film to increase the conductivity and furthermore, to obtain a p-n junction.
In this study, the helicon sputtering system was employed to grow the epitaxial Si-doped AlN thin film on sapphire substrate. It has been confirmed
that by adjusting the diameter of silicon chips placed on Al target, the doping concentration can be controlled. The aluminum contacts were fabricated on the Si-doped AlN film for the electrical property measurements. The special
resistivity of about 10^7~10^8 ohm-cm^2 was obtained by the TLM measurement. The MESA structure was fabricated and the special hall bar electrodes were designed for the four-point measurement to obtain the high resistivity of the film.According to the results, with the doping concentration of 10^20 cm^-3, the resistivity, the electron concentration and the mobility of the Si-doped AlN are about 3.3×10^6 ohm-cm^2, 3.1×10^11 cm^-3 and 6.1 cm^-2/V-s, respectively.

並列關鍵字

Si-doped AlN ； sputtering ； mobility ； wind band gap ； AlN ； resistivity

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