具功能性的有機薄膜封裝保護層在非晶態銦鎵鋅氧化物半導體薄膜電晶體之探討

Abstract

雖然非晶態銦鎵鋅氧化物半導體薄膜電晶體具有非常高的載子遷移率，但銦鎵鋅氧化物在大氣環境中不穩定，因此需要封裝保護層來隔絕與大氣中的接觸以達元件長時間操作的穩定性。相較其他有機材料PTFMA和PMMA具有較高的材料密度和較高的介面疏水性，在本文中被提出用來做為封裝保護層，當元件沉積PTFMA後，臨界電壓偏移了2.3伏特;沉積PMMA後偏移了6.4伏特，兩者都展現了非常好的環境穩定性，諸如次臨界區飄移、臨界電壓、載子遷移率都只有些許的改變。最後具彩色濾光片功能性的有機封裝保護層被提出，元件達到49%的NTSC標準。整體來說有機封裝保護層具有非常高的潛力在低沉積損傷、顏色功能性、噴塗，結合這些優勢不論是製程機台或是材料的成本都可以被大幅度的降低。

The amorphous indium-gallium-zinc oxide (a-IGZO) channel thin-film transistor (TFTs) has high mobilites. However, the IGZO is not chemical stable in ambience; hence the passivation layer is essential for the devices long term stability. Thus the organic passivation PTFMA and PMMA were proposed, due to their high material density (compare with other organic polymer) and hydrophobic feature. An a-IGZO with PTFMA shows a 2.3V threshold voltage (VTh) shift, another with PMMA shows VTh=6.4V shift, both devices revealed good stability in ambience; The sub-threshold swing (s.s.), VTh, and mobilities (μsat) changed only slightly. Finally, the functional color filter passivation layers were demonstrated, the colored passivation showed 49% National Television Systems Committee (NTSC) standard. In general, organic passivations provided a high potential passivation process for lowering deposition damage, functional color filter, printable, easy process, and lowering cost. These merits in organic passivation can also reduce the equipment and material costs.