Microscopic modeling of the dielectric properties of silicon nitride
Microscopic modeling of the dielectric properties of silicon nitride
复制标题
氮化硅介电特性的微观建模
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
G. Galli
中科院分区：
文献类型：
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作者：
T. Pham;Tianshu Li;S. Shankar;F. Gygi;G. Galli
We investigate the differences between the dielectric properties of bulk silicon nitride and thin films, in both crystalline and amorphous structures. We show that to correctly account for the decrease of the optical (${ensuremath{epsilon}}_{ensuremath{infty}}$) and static (${ensuremath{epsilon}}_{0}$) dielectric constants at the nanoscale, it is necessary to take into account their spatial variations within the film and at the surface. A model based on the assumption of abrupt interfaces between vacuum and the film surfaces predicts the wrong trend of the dielectric properties as a function of the film thickness, i.e., an increase of ${ensuremath{epsilon}}_{ensuremath{infty}}$ and ${ensuremath{epsilon}}_{0}$ as the dimension of the film decreases. We also show that a first-principles description of the structural properties of amorphous bulk and thin films is necessary, in order to obtain structural properties in agreement with experiment, and thus electronic and dielectric properties consistent with available measurements.
We investigate the differences between the dielectric properties of bulk silicon nitride and thin films, in both crystalline and amorphous structures. We show that to correctly account for the decrease of the optical (${ensuremath{epsilon}}_{ensuremath{infty}}$) and static (${ensuremath{epsilon}}_{0}$) dielectric constants at the nanoscale, it is necessary to take into account their spatial variations within the film and at the surface. A model based on the assumption of abrupt interfaces between vacuum and the film surfaces predicts the wrong trend of the dielectric properties as a function of the film thickness, i.e., an increase of ${ensuremath{epsilon}}_{ensuremath{infty}}$ and ${ensuremath{epsilon}}_{0}$ as the dimension of the film decreases. We also show that a first-principles description of the structural properties of amorphous bulk and thin films is necessary, in order to obtain structural properties in agreement with experiment, and thus electronic and dielectric properties consistent with available measurements.