In Situ Process Control of Trilayer Gate-Stacks on p-Germanium With 0.85-nm EOT
In Situ Process Control of Trilayer Gate-Stacks on p-Germanium With 0.85-nm EOT
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DOI：
10.1109/led.2015.2459663
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发表时间：
2015-07
影响因子：
4.9
通讯作者：
Y. Zheng;A. Agrawal;G. Rayner;M. Barth;K. Ahmed;S. Datta;R. Engel-Herbert
中科院分区：
文献类型：
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作者：
Y. Zheng;A. Agrawal;G. Rayner;M. Barth;K. Ahmed;S. Datta;R. Engel-Herbert
在原子层沉积（ALD）反应器中，利用椭圆偏振光谱技术对Ge上HfO 2/Al 2 O3/GeOx三层介质栅堆叠工艺进行了快速、合理的优化。这种方法的好处是通过开发一个完整的过程在原位证明：1）自然氧化物去除氢等离子体; 2）控制再氧化Ge表面钝化;和3）使用热ALD的Al 2 O3和HfO 2的沉积。低k层厚度按比例缩小而不失去它们各自的功能，即，GeOx以与Ge和Al 2 O3形成电性能良好的界面，从而在电学上稳定GeOx/Ge界面。侵略性的等效氧化物厚度缩放的三层堆栈下降到0.85 nm，在VFB- 1 V的0.15 mA/cm 2的低栅极泄漏实现，同时保持高品质的电介质-半导体界面。
In situ spectroscopic ellipsometry was utilized in an atomic-layer-deposition (ALD) reactor for rapid and rational gate stack process optimization of the trilayer dielectric HfO2/Al2O3/GeOx on Ge. The benefit of this approach was demonstrated by developing an entire process in situ: 1) native oxide removal by hydrogen plasma; 2) controlled reoxidation for Ge surface passivation; and 3) deposition of Al2O3 and HfO2 using thermal ALD. The low-k layer thicknesses were scaled down without losing their respective functions, i.e., GeOx to form an electrically well behaved interface with Ge and Al2O3 to thermodynamically stabilize the GeOx/Ge interface. Aggressive equivalent-oxide-thickness scaling of the trilayer stack down to 0.85 nm with a low gate leakage of 0.15 mA/cm2 at VFB- 1 V was achieved, while preserving a high-quality dielectric-semiconductor interface.