雷射退火在氧化物半導體與薄膜電晶體的應用

Applications of Laser Annealing on Oxide Semiconductors and Thin Film Transistors

陳竑暐(Hong-Wei Chen)

指導教授 ： 吳忠幟

國立臺灣大學/電機資訊學院/光電工程學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.03130

摘要

西元1960年由美國科學家Maiman發表了第一台紅寶石雷射，自此以後雷射的應用開始普及於工業、通訊、醫療、量測等產業。近年來，雷射也常被應用於顯示器和半導體產業，利用雷射高功率密度的性質，雷射退火常用於加熱非晶矽使其成為多晶矽，進而製作出低溫多晶矽薄膜電晶體。
氧化物半導體由於擁有低溫成長、透明、高載子移動率等特色，近來吸引許多研究投入，其中尤其以顯示器產業與軟性電子相關產業最為興盛，甚至有機會取代傳統非晶矽薄膜電晶體成為主流。
在本論文中，我們嘗試將雷射應用在氧化銦鎵鋅半導體，首先利用TLM的結構研究雷射退火製程對於金屬-非金屬之間接觸電阻的影響，我們發現控制適當的雷射製程條件，可以使金屬電極與氧化銦鎵鋅間的接觸電阻率降至6.5×10^5Ω-cm^2，並且研究不同成長條件的氧化銦鎵鋅對於接觸電阻的影響。
接著我們利用雷射退火降低金屬和半導體間串聯阻抗的特性，製作上閘極self-aligned氧化銦鎵鋅薄膜電晶體，以達到減少光罩數目、增加開口率、精確控制半導體通道長度等優點。

關鍵字

雷射退火 ； 氧化銦鎵鋅 ； 上閘極自我對準式薄膜電晶體 ； 氧化物半導體

並列摘要

Since in 1960 the American scientist Maiman reported the first ruby laser, lasers have been widely used in many industries, such as communication, medical industry, and measurements etc. In recent years, lasers also have been applied to the display and semiconductor industries. Because of the capability of high power densities, the laser processing is commonly used in the fabrication of poly silicon TFTs, to crystallize amorphous silicon.
Oxide semiconductors have also gained increasing attention in recent years due to merits such as low fabrication temperature, transparency, and high mobility even in the amorphous phase. These benefits of oxide semiconductors render their high potential to replace a-Si and poly-Si TFTs.
In this thesis, we applied the laser processing on the IGZO semiconductors and TFTs. First we used the TLM test structure to study the effects of laser processing on the metal-semiconductor contact resistances. We found that by proper laser processing conditions, the specific contact resistivity could go down to 6.5×10-5Ω-cm2. In addition, we studied the effects of the IGZO growth conditions on the contact resistances.
With these, we fabricated top-gate self-aligned IGZO TFTs utilizing laser processing. The top-gate self-aligned TFT structure has the benefits such as reduction of the mask count, increase in the aperture ratio, and precise control of the channel length.

並列關鍵字

laser annealing ； IGZO ； self-aligned top-gate thin film transistors ； oxide semiconductors

參考文獻

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