Effect of Nitrogen on the Electronic Properties of Hafnium Oxynitrides
Effect of Nitrogen on the Electronic Properties of Hafnium Oxynitrides
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DOI：
10.1063/1.2177385
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发表时间：
2006-02
期刊：
影响因子：
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通讯作者：
Jongwoo Choi;R. Puthenkovilakam;Jane P. Chang
中科院分区：
文献类型：
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作者：
Jongwoo Choi;R. Puthenkovilakam;Jane P. Chang
第一性原理模拟被用来确定不同氮浓度下的氧氮氢化合物的电子结构。在密度泛函理论的框架下，用平面波赝势方法研究了氮掺杂对氮氧化物的态密度和禁带宽度的影响。由于N_2p态扩展到t-HfO_2的带隙中，禁带宽度随N浓度的增加而减小。用基于t-HfO2的(t-HfO2)5(Hf3N4)和(t-HfO2)(Hf3N4)结构计算了HfOxNy/Si界面的能带排列。(t-HfO2)5(Hf3N4)和(t-HfO2)(Hf3N4)的价带偏移量分别为1.47 eV和1.14 eV，明显小于HfO2/SiT∼3.0 eV的报道。
First principles simulations are used to determine the electronic structures of hafnium oxynitrides with various nitrogen concentrations. The effect of nitrogen incorporation on the density of states and the band gaps of hafnium oxynitrides are examined by the plane-wave pseudopotential method in the framework of density functional theory. The band gap decreases with increasing N concentration due to the extension of N 2p states into the band gap of t-HfO2. The band alignment at the HfOxNy∕Si interface is calculated using the t-HfO2 based (t-HfO2)5(Hf3N4) and (t-HfO2)(Hf3N4) structures. The estimated valence-band offsets are 1.47 and 1.14 eV for (t-HfO2)5(Hf3N4) and (t-HfO2)(Hf3N4), respectively, which are significantly smaller than the reported value for HfO2∕Siat∼3.0eV.