|本期目录/Table of Contents|

 硅薄膜导热系数微尺度效应的临界尺寸(PDF)

《纳米技术与精密工程》[ISSN:1672-6030/CN:12-1351/O3]

期数:
2014年3期
页码:
176-181
栏目:
精密测量
出版日期:
2014-05-15

文章信息/Info

Title:
 Critical Size for Microscale Effect of Silicon Film Thermal Conductivity
作者:
 苏高辉12 杨自春12 孙丰瑞2
 (1.海军工程大学舰船高温结构复合材料研究室,武汉430033;
2.海军工程大学动力工程学院,武汉430033)
Author(s):
 Su Gaohui12 Yang Zichun12 Sun Fengrui2
 (1.Institute of High Temperature Structural Composite Materials for Naval Ship, Naval University of Engineering, Wuhan 430033, China;

2.College of Power Engineering, Naval University of Engineering, Wuhan 430033, China)

关键词:
 硅薄膜 蒙特卡洛方法 导热系数 声子热输运 尺度效应
Keywords:
 silicon film Monte Carlo method thermal conductivity phonon heat transport scale effect
分类号:
TK124
DOI:
10.13494/j.npe.20130086
文献标识码:
A
摘要:
 基于灰介质假设及拟合的色散关系,采用蒙特卡洛方法对微纳米硅薄膜内的声子热输运特性进行了模拟.将3 μm厚的硅薄膜导热系数的计算结果与文献结果进行了对比,二者吻合较好.分析了厚度对薄膜内温度场及导热系数的影响.结果表明,当厚度小于某一尺度时,薄膜导热系数会随着厚度的减小而降低,呈现尺度效应;薄膜内温度场也不再是线性分布,而是在边界处呈现阶跃特性,且随着厚度减小,温度阶跃增大.基于该方法求得了 100 ~ 400 K 温度区间内,硅薄膜法向导热系数出现明显尺度效应的临界尺寸.计算发现,随着温度的升高,临界尺寸变化范围很大,平均温度为100 K时,临界尺寸约为50 μm,平均温度为400 K时,临界尺寸约为2.5 μm,前后相差了一个数量级.
Abstract:
 Based on the gray media approximation and the fitted dispersion relation, the phonon heat transport in micronano silicon films was simulated with the Monte Carlo method. The predicted thermal conductivity (TC) of silicon film with 3 μm thickness was in good agreement with literature results. The effect of the thickness on the temperature field and cross-plane TC of the silicon films was analyzed. The results show that when the thickness is less than a certain scale, the TC of the film decreases with the decrease in thickness, which exhibits scale effect; the temperature field is not in linear distribution, but shows discontinuous characteristics at the boundary, and as the thickness decreases, the temperature discontinuity degree increases. The critical size at which TC begins to show obvious scale effect was obtained at the temperature range between 100 K and 400 K. Calculated results show that as the temperature increases, the critical size decreases sharply. When the average temperature is 100 K, the critical size is about 50 μm; when the average temperature is 400 K, the critical size is about 2.5 μm, which shows a difference of an order of magnitude.

参考文献/References

备注/Memo

备注/Memo:
收稿日期: 2014-03-12.
基金项目: 总装十二五预研基金资助项目( 401030603).
作者简介: 苏高辉(1988— ),男,博士.
通讯作者: 苏高辉,sugaohui@163.com.
更新日期/Last Update: 2014-08-14