退火溫度和表面處理對IGZO元件的影響

Effect of anneal temperature and plasma treatment on the performance of IGZO

高逸群(Yi-Chun Kao)

指導教授 ： 吳耀銓

國立交通大學/工學院/工學院半導體材料與製程設備學程/碩士(2011年)

https://doi.org/10.6842/NCTU.2011.00354

摘要

近年來平面顯示器的規格隨著面板尺寸越來越大及解析度越來越高的需求，對陣列製程的要求也越來越嚴格，例如金屬導線對阻抗值的要求，由早期的Mo製程，到後來的鋁合金製程，到現在常用的純鋁製程，接下來的銅製程，這些製程不斷改進，都是為了解決面板在大型化和高解析度化後所面臨的RC負載問題。解決面板的導線阻抗問題後，再來則是寄生電容的負載問題和元件的充電問題。從常用的非晶矽元件發展到低溫多晶矽元件，主要是為了提升元件充電能力，進而
縮小元件尺寸。
雖然低溫多晶矽元件可以改善非晶矽元件的元件特性，但設備投資成本較高，且元件均勻性容易因為雷射退火條件不易控制，而造成元件均勻性不佳。
因此，有許多研究單位和面板製造商投資大量成本來開發氧化物半導體，從早期的ZnO元件到後來各種不同的氧化物半導體，都相繼發表。但氧化物半導體最大的問題則是元件穩定性不佳，所以，各家製造商都會在現有材料中摻雜各種不同的元素，改善元件穩定性。
目前最熱門的其中一個材料就是氧化銦鎵鋅，也被視為最有機會取代非晶矽材料之一，因此我們也希望利用不同的退火條件和表面處理的方式來改善氧化銦鎵鋅元件穩定性，進而開發適合氧化銦鎵鋅元件的製程流程。所以我們對IGZO薄膜做以下不同退火參數和表面處理參數的探討。
在330oC的退火溫度下，可以得到比較高的導通電流，若再經過N2O電漿表面處理後的元件，其元件的穩定度也會相對的提高。元件在經過N2O表面處理和2個小時的330oC退火後元件的Ion電流為6.4E-5A，mobility 11 cm2/V-s，元件在Vgs 50V；Vd=Vs=0V條件下劣化，在經過2000秒後，啓始電壓漂移量為2.62V；元件在Vgs 5Vh和Vd=15V andVs=0條件下劣化，在經過2000秒後，啓始電壓漂移量為0.44V。

關鍵字

氧化物半導體

並列摘要

In recent years, as far as the specifications of the flat panel displays are concerned, with the need to scale up the panel size and increase the resolution, the requirements of the array process are becoming more demanding. Take the requirement of the metal line resistance for example, the processes have been improved from the earlier Mo process, Al alloy process, pure Al process used frequently
nowadays, to the coming Cu process, all of these process improvements have been made to solve the problem on the RC load effect faced with while scaling up the panels and increasing the resolution. After solving the problem on the metal line resistance of panels, there still are problems on the parasitic capacity loading effect and the device charging. The main purpose to develop the frequently used Amorphous Silicon devices into Low Temperature Poly Silicon devices is to improve the charging ability of devices, and further, to shrink the device size.
Although Low Temperature Poly Silicon devices can improve the
device performance of Amorphous Silicon devices, the costs of facility
investment are higher and the device uniformity would be subject to
the laser anneal conditions and becomes hard to control, which would
in turn result in the bad device uniformity.
Therefore, a great number of the research institutes and the LCD
makers are investing an enormous amount of money to develop the metal oxide semiconductors. The earlier ZnO devices and later metal oxide semiconductors have been sequentially launched. The biggest problem, however, is that the device stability is not good. Therefore, every manufacturer now is doping various elements into the current aterials in order to improve the device stability.
Currently, one of the most popular materials is IGZO which is
considered as one of the materials that are most likely to replace
Amorphous Silicon. So we also hope to utilize different thermal
anneal conditions and plasma treatment methods to improve the
IGZO device stability, and further, to develop the process flows that
are suitable for the IGZO devices. That is why we are probing into
the IGZO thin film with various thermal anneal parameters and
plasma treatment parameters as follows.
Devices can get a higher operation current after 330oC anneal.
And the IGZO film use the N2O treatment, the devices will get
a better stability. Devices using the N2O surface treatment and
2hr 330oC final anneal, Ion of the devices is about 6.4E-5A, the
mobility of the devices is about 11 cm2/V-s, the Vth shift of
the device is about 2.62V at stress time 2000 seconds in Vgs
50V and Vd=Vs=0V. the Vth shift of the device is about 0.44V
at stress time 2000 seconds in Vgs 5V and Vd 15V and Vs 0V。

並列關鍵字

Metal oxide semiconductor

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