Carrier transport in HfO/sub 2//metal gate MOSFETs: physical insight into critical parameters
Carrier transport in HfO/sub 2//metal gate MOSFETs: physical insight into critical parameters
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DOI：
10.1109/ted.2006.870888
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发表时间：
2006-03
影响因子：
3.1
通讯作者：
M. Cassé;L. Thevenod;B. Guillaumot;L. Tosti;F. Martin;J. Mitard;O. Weber;F. Andrieu;T. Ernst;G. Reimbold;T. Billon;M. Mouis;F. Boulanger
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文献类型：
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作者：
M. Cassé;L. Thevenod;B. Guillaumot;L. Tosti;F. Martin;J. Mitard;O. Weber;F. Andrieu;T. Ernst;G. Reimbold;T. Billon;M. Mouis;F. Boulanger
通过4.2K以下的低温测量，对HfO/sub 2//金属栅MOSFET中的电子和空穴迁移率进行了深入的研究.原始的技术分裂允许不同散射机制的去相关。研究发现，即使当电荷陷阱可以忽略不计时，由于固定电荷或偶极子引起的强烈的远程库仑散射（RCS）也会导致迁移率的大部分下降。发现有效电荷分布在HfO/sub 2/SiO/sub 2/界面附近的2nm范围内。在HfO/sub 2//SiO/sub 2/界面上使用7/spl × 10/sup 13/ cm/sup-2/固定电荷计算RCS，与实验结果吻合较好。我们还讨论了远程声子散射的作用，在这样的门堆栈。HfO/sub 2/与表面软光学声子的相互作用清楚地证明了金属栅极，但仍然是第二顺序。所有这些远程相互作用是显着的界面氧化物厚度高达2纳米，超过这一点，这些是可以忽略不计的。最后，金属栅极（TiN）本身引起修改的表面粗糙度项，其甚至对于SiO/sub 2/栅极电介质参考影响低到高的有效场迁移率。
Electron and hole mobility in HfO/sub 2//metal gate MOSFETs is deeply studied through low-temperature measurements down to 4.2 K. Original technological splits allow the decorrelation of the different scattering mechanisms. It is found that even when charge trapping is negligible, strong remote coulomb scattering (RCS) due to fixed charges or dipoles causes most of the mobility degradation. The effective charges are found to be located in the HfO/sub 2/ near the SiO/sub 2/ interface within 2 nm. Experimental results are well reproduced by RCS calculation using 7/spl times/10/sup 13/ cm/sup -2/ fixed charges at the HfO/sub 2//SiO/sub 2/ interface. We also discuss the role of remote phonon scattering in such gate stacks. Interactions with surface soft-optical phonon of HfO/sub 2/ are clearly evidenced for a metal gate but remain of second order. All these remote interactions are significant for an interfacial oxide thickness up to 2 nm, over which, these are negligible. Finally, the metal gate (TiN) itself induces a modified surface-roughness term that impacts the low to high effective field mobility even for the SiO/sub 2/ gate dielectric references.