低溫電漿處理之多晶氧化錫通道結構於薄膜電晶體及光偵測器之研究

Study on the Characteristics of Thin-Film Transistor and Photodetector Based on Plasma-Modified Polycrystalline Tin-Oxide Channels

陳柏維(Chen Po-Wei)

指導教授 ： 程金保 ； 鄭淳護

國立臺灣師範大學/科技與工程學院/機電工程學系/碩士(2016年)

https://doi.org/10.6345/NTNU202204420

摘要

本研究使用磁控濺鍍製作P型氧化亞錫通道層，並透過改變環境退火氣體、退火溫度和退火時間，來改善氧化亞錫通道層品質，以期得較佳的氧化亞錫通道特性。此最佳化後的P型氧化亞錫薄膜電晶體特性，其臨界電壓為-0.83 V，載子遷移率為5.4 cm2/Vs，開關電流比為1.24×104。為了進一步提升P型氧化亞錫薄膜電晶體特性，我們同步使用了低溫氟電漿來改質P型氧化亞錫薄膜品質，透過氟原子對氧化錫通道層進行缺陷修補。經實驗結果證明，與無氟電漿改質的電晶體特性相比，經過低溫氟電漿改質處理之氧化亞錫電晶體元件，其開關電流比，有效改善了1個多數量級以上，可達到7.7x105。另一方面，我們也使用了氧電漿改質氧化亞錫薄膜，探討不同電漿源氣體對氧化亞錫通道層的影響。經200瓦氧電漿改質條件下，可改變通道氧化亞錫中得錫氧比，得到一個富氧型的N型二氧化錫通道。其電晶體元件特性所量測而得的臨界電壓為-1.49 V，載子遷移率可高達30 cm2/Vs，且開關電流比為7.8x103。此外，我們也探討了氧化錫電晶體的照光特性，實驗結果也發現其光響應行為與通道極性有高度相關性。P型氧化亞錫薄膜電晶體在可見光紅、綠、藍三波長下具有明顯光電流響應行為，而N型二氧化錫薄膜電晶體則僅對短波長藍光有較明顯的反應。此高靈敏性且高選擇比的光響應特性，未來將有機會整合應用於光偵測器產品上。

關鍵字

薄膜電晶體 ； 氧化錫 ； 電漿改質 ； 光感測器

並列摘要

In this work, the low-temperature plasma treatment was employed to modify the polarity of tin-oxide (SnO) semiconductor and investigated the potential applications of SnO thin-film transistors. The intrinsic p-type SnO TFT showed a low threshold voltage of -0.81 V, a field-effect mobility of 5.4 cm2 V −1 s −1 , and on/off current ratio of 2.28×103. To further improve the performance of intrinsic TFT devices, the low-temperature fluorine plasma treatment was conducted on p-type SnO channel. Under a variety of experimental comparison, the p-type SnO TFT with fluorine plasma treatment showed the significant improvement on current ratio by at least one order of magnitude (7.7x105), which could be attributed to the passivation effect of fluorine atoms on SnO channel. We also investigate the oxygen plasma effect on intrinsic p-type SnO channel. After an appropriate oxygen plasma treatment, the p-type SnO channel transferred to be n-type one due to the increase of oxygen concentration. The optimal n-type SnO TFT exhibited a threshold voltage of -1.49 V, a high field-effect mobility of 30 cm2 V −1 s −1, and on/off current ratio of 7.8x103. Therefore, the channel modification engineering by simple plasma treatment could be useful for the fabrication of low-temperature electronics. Besides, the illumination test of visible light was also performed to evaluate the carrier response between n- and p-type tin-oxide channels. The current response of transistor dependent to bandgap of SnO channel (n- or p-type) and light wavelength showed the potential application of Photodetector.

並列關鍵字

Thin Film Transistor ； Tin Oxide ； Plasma Treatment ； Photodetector

參考文獻

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