NH3電漿氮化技術在Hf-silicate/Gd/TaC NMOSFET上之研究

The Device of TaC/Gd/Hf-based Gate nMOSFETs with NH3-plasma Treatment

陳啓文(Chii-Wen Chen)；鍾宜佐(Yi-Zuo Zhong)；黃正全(Zheng-Quan Huang)；陳育廷(Yu-Ting Chen)；宋大偉(Da-Wei Song)

高介電金屬閘極 ； 缺陷密度 ； 閘極漏電流 ； high-k/metal-gate ； trap densities ； gate leakage

明新學報

39卷1期（2013 / 02 / 01）

1 - 8

繁體中文

在這項研究中，我們以Gadolinium（Gd）為覆蓋層（Capped layer）的高介電常數絕緣層／金屬閘極（High-k/Metal-gate），利用NH3電漿（NH3-plasma）處理過後對其High-k中缺陷密度做研究。觀察發現，經過NH3-plasma處理的元件有較高的汲極電流以及較低的閘極漏電流。我們更進一步利用變頻Charge-pumping的量測來萃取缺陷密度的縱深分布。發現電漿氮化的元件有較少的缺陷密度。因此我們提出在High-k中加入氮原子抑制Gd擴散到高介電係數的閘極絕緣層裡以降低缺陷密度。

In this work, the effect of post NH3-plasma treatment on trap density of high-k/metal-gate nMOSFETs with gadolinium (Gd) cap layers was investigated. We found that the device had high drain current and low gate leakage after NH3-plasma nitridation. Moreover, we used charge-pumping measurement with various frequency to extract the depth profile of trap density. It was observed that NH3 plasma nitridation devices could have fewer trap density. Thus, we deduce that the nitrogen incorporation can reduce the Gd-induced trap densities due to the suppression of Gd diffusion into the high-k gate dielectric.

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