本論文以氧化鉿（HfOx）作為有機薄膜電晶體絕緣層，具光配向的聚亞醯胺（Photoaligned Polyimide, PA- PI）為元件修飾層，藉由氧化鉿的高介電常數特性與PA-PI的非極性表面特性來製作可低電壓操作之五環素（pentacene）薄膜電晶體，並進一步研究以線性偏極化UV光照射PA-PI表面使其產生光裂解（photo-degradation）後，五環素分子成長情形與電晶體的特性。
　　實驗結果發現，氧化鉿在加上PA-PI修飾層後，電晶體的漏電流成功降低了兩個數量級，在1 MV/cm下操作只有10-8 ~ 10-9 A/cm2，且電容值為26.41 nF/cm2，成功製作出臨界電壓只有-1.63 V的五環素薄膜電晶體。在原子力顯微鏡、X-ray光譜、拉曼光譜之分析中，顯示了氧化鉿電晶體加了PA-PI後，五環素薄膜之表面約有1 m的晶粒大小與樹枝狀的表面形態，內部堆疊有較好的結晶程度與結晶區域大小，以及堆疊較為緊密，而再組織能也較低。
　　另一方面，實驗發現PA-PI經過偏極化UV曝光後，五環素分子會沿著垂直UV偏極化方向排列成長，且電晶體通道中的載子也較易在垂直UV偏極化方向上傳輸，因此電晶體在垂直與平行UV偏極化方向上具有載子遷移率之異向性比，載子遷移率最大可差1.74倍，載子遷移率最高為0.160 cm2/Vs。透過偏振拉曼光譜分析也證實，五環素薄膜成長在曝光的PA-PI表面上時，在垂直UV偏極化方向上的分子間作用力較強。此外，還發現電晶體的臨界電壓會隨著PA-PI曝光量而有所變化，且在電容量測中，平帶電壓也有相同的變化，可知電晶體的臨界電壓可藉由PA-PI的曝光量來控制。因此，我們不只成功製作出可低電壓操作的有機薄膜電晶體，還成功研究出具有載子遷移率的異向性與可控的臨界電壓之有機薄膜電晶體。

In this study, pentacene-based thin-film transistors (TFTs) operated at low voltage have been realized by employing hybrid dielectrics, photoaligned polyimide (PA-PI)-capped high-k hafnium oxide (HfOx). The PA-PI layer plays a role in modifying the surface characteristic of the HfOx layer. While a PA-PI film was coated onto HfOx, the leakage current density dropped more than two orders of magnitude to 10-9 A/cm2 at 1 MV/cm; therefore, the pentacene-based TFTs exhibited high performance operated at low voltage. Furthermore, the PA-PI films were irradiated with linearly polarized UV beams at various doses. The grain growths of the pentacene film were perpendicularly oriented to the polarized direction of the UV irradiation on the PA-PI layer. The mobility anisotropic ratios, which are defined as the drain current flows parallel or perpendicular to the orientation of the pentacene films, were obtained. The maximum anisotropic ratio was 1.74. Interestingly, we have demonstrated a tunable threshold voltage and flatband voltage of OTFTs by controlling the dose of UV light.

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