HfO2 gate dielectric on (NH4)2S passivated (100) GaAs grown by atomic layer deposition
HfO2 gate dielectric on (NH4)2S passivated (100) GaAs grown by atomic layer deposition
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DOI：
10.1063/1.2838471
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发表时间：
2008-02-01
影响因子：
3.2
通讯作者：
Chui, C. O.
中科院分区：
文献类型：
--
作者：
Chen, P. T.;Sun, Y.;Chui, C. O.
研究了原子层沉积法生长的氧化铟与经盐酸清洗和(NH_4)(2)S钝化处理的(100)Ga As之间的界面。同步辐射光电子能谱表明，砷化镓表面的天然氧化物被成功去除，并形成了钝化的硫化物。逐层去除Hafnia薄膜的结果表明，在介质沉积过程中，在界面处形成了少量的As_2O_3。在450℃的后沉积退火后，观察到微量的砷和硫向外扩散到Hafnia薄膜中，这可能是电活性缺陷的根源。透射电子显微镜的横截面图像显示，与未处理的样品相比，在硫磺处理的样品上暴露于给定的前驱体表面的HfO2膜更厚。此外，在HfO2/GaAs界面处的价带和导带的偏移量分别为3.18 eV和0.87-1.36 eV。结果表明，HCl+(NH4)(2)S处理对砷化镓化学钝化和原子层沉积的初始表面有较好的钝化效果。(C)2008年美国物理研究所。
The interface between hafnium oxide grown by atomic layer deposition and (100) GaAs treated with HCl cleaning and (NH4)(2)S passivation has been characterized. Synchrotron radiation photoemission core level spectra indicated successful removal of the native oxides and formation of passivating sulfides on the GaAs surface. Layer-by-layer removal of the hafnia film revealed a small amount of As2O3 formed at the interface during the dielectric deposition. Traces of arsenic and sulfur out diffusion into the hafnia film were observed after a 450 degrees C postdeposition anneal and may be the origins for the electrically active defects. Transmission electron microscopy cross section images showed thicker HfO2 films for a given precursor exposure on sulfur treated GaAs versus the nontreated sample. In addition, the valence-band and the conduction-band offsets at the HfO2/GaAs interface were deduced to be 3.18 eV and a range of 0.87-1.36 eV, respectively. It appears that HCl+(NH4)(2)S treatments provide a superior chemical passivation for GaAs and initial surface for atomic layer deposition. (c) 2008 American Institute of Physics.