電漿輔助化學氣相沉積有機絕緣層應用於可撓曲薄膜電晶體

Plasma Enhanced Chemical Vapor Deposited Organic Dielectric Layer Used In Flexible Organic Thin Film Transistor

張志偉(Chih-wei Chang)

指導教授 ： 蕭桂森

國立暨南國際大學/科技學院/應用材料及光電工程學系/碩士(2016年)

摘要

目前顯示器的應用非常廣泛，舉凡：手機、電視、電腦螢幕、百貨公司大型電視機……等等，由其以手機的應用更為重要，現代人幾乎人手一機，顯現了手機對人們生活的便利性。在手機顯示器的應用上還是以硬性的基板為主，因此當手機尺寸稍大時便會造成收納的困擾若不小心放在後口袋而座到或壓到，這台手機便幾乎不堪使用，且目前智慧型手機的功能非常多，耗電量也相對比以前較大，而其中螢幕對耗電量所佔的比重相當大，因此本篇論文朝向將螢幕中的電晶體元件製作成可撓曲以及低工作電壓的研究為目標。
近年來對於P型有機材料的研究相當多，因為其材料在大氣下相對穩定，因此本篇論文便使用Pentacene做為有機半導體層的材料，在有機半導體層製成部分，使用熱蒸鍍（Thermal Evaporation）來製作，將基板溫度控制在65℃以及高真空度下，因基板溫度較低在使用塑膠基板較不會出現熱捲曲、熱變形的問題。在絕緣層的部分，有鑑於半導體層使用有機材料，便希望藉由製作有機絕緣層使其與有機半導體層的附著性更好而讓有機薄膜電晶體元件效能更佳，有機絕緣層製成部分，使用電漿輔助式化學氣相沉積（Plasma Enhanced Chemical Vapor Deposition），將製成溫度控制在室溫以及低真空度下製作，以三甲基鋁為前驅物製作出有機絕緣層並透過參數的變化（RF功率、氮氣氣體量、三甲基鋁氣體量、時間、真空度、溫度）將其應用在有機薄膜電晶體上實現可撓曲、低工作電壓，藉由先確保以矽基板製作成的有機薄膜電晶體能夠正常運作為基礎，再延伸應用至ITO軟性基板上。經過研究發現，在RF功率100W、氮氣氣體量10mln/min 、三甲基鋁氣體量5 g/h 、時間20分鐘、混和溫度130℃，所得到的有機絕緣層電容值比二氧化矽來的高，且應用在ITO軟性基板所製作成的有機薄膜電晶體元件其載子遷移率為230.2 cm2/Vs、啟動電壓為-1.3418 V、開關比為約500，並具備可撓曲的特性。

關鍵字

熱蒸鍍 ； P型材料 ； 有機薄膜電晶體 ； 可撓曲 ； 電漿輔助式化學氣相沉積

並列摘要

Until now, the application of display is very wide. For example, Television, Cell phone, Computer monitor, large size display and so on. The most important application is cell phone. In recent years, Cell phone becomes the most important of personal equipment because in this small machine you can do a lot of things. For instant, shopping, seeing other people's daily life, pay bill, order ticket and so on. It show the convenience of function that cell phone bring to us. The display substrate which cell phone used still hard substrate. Because of that, you will face some problems on it. The size of cell phone is too big. It can't be put in your pocket. When you sit down on the chair and you hear the voice which sounds like heartbreak. You may know that your cell phone was broken. The power consumption of Cell phone's monitor is very big .It would cause the endurance of cell phone. According to the above problems, this thesis make two research objectives in the organic thin film transistor. First is flexible. Second is low-power.
In recent years, there are a lot of researches on P-type organic semiconductor because P-type semiconductor is stable in the atmosphere. This thesis chose Pentacene to be organic thin film transistor's semiconductor layer. In the fabrication of semiconductor layer, this thesis use thermal evaporation. It would be important to control the substrate temperature in 65℃ and maintain high vacuum. Because of low temperature of substrate, the plastic substrate can be maintained original form. When the substrate temperature is too high, it would cause the plastic distorted or deform. In the fabrication process of insulator layer, this thesis use plasma enhanced chemical vapor deposition. Because semiconductor layer use organic material, this thesis use organic material in the insulator to enhance the adhesion of semiconductor layer and insulator layer. For the same reason that in fabrication of plastic substrate, the substrate temperature control in the room temperature and maintain low vacuum. Use TMAl to be precursor in fabrication of organic insulator. Through the changes of parameters（RF power、N2 flow rate、TMAl flow rate、Time、Vacuum、Mixed Temperature）. After many experiment, the parameters of RF power 100W、N2 flow rate 10mln/min、TMAl flow rate 5 g/h、20min、Mixed Temperature 130℃ could make the thin film's capacitance which higher than SiO2. In order to make sure that the organic thin film transistor can work. This thesis starts from silicon hard substrate. When the silicon based organic thin film transistor can work, it can be continue to the application of ITO flexible substrate. According to the above conditions, the organic thin film transistor can be fabricated. The device efficiency index of mobility、on/off rate、threshold voltage can be measure to be 230.2 cm2/Vs、-1.3418 V、500 and have the property of flexible.

並列關鍵字

Thermal evaporation ； P-type material ； Organic thin film transistor ； Flexible ； Plasma enhance Chemical Vapor Deposition

參考文獻

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