微热板中微纳空气间隙传热特性研究

Research on thermal conductance characteristics of submicron gas gap of micro-hotplate

在微热板(MHP)的应用过程中,其本身的热特性是影响器件性能的重要因素之一,同时加热电极和衬底之间的气体间隙传热是影响MHP热特性的一个关键因素。采用标准CMOS工艺和简单的postCMOS工艺,设计制作了一种具有550 nm空气间隙的MHP,在热稳态下利用MHP的自加热效应测得了空气间隙的传热热导,结果表明:截面积为35μm×35μm、厚550 nm的空气间隙的热导为6.74×10-5W/K,MHP的整体热导为7.51×10-5W/K,可见在MHP热耗散中,空气间隙传热占主导地位。

In recent years,micro-hotplate（ MHP） is widely used to make thermal sensors,heating compo-nents,infrared emitters,and power generators. In MHP application,its own thermal characteristics is one of the important factors that affect device performance and as well as the heat transfer characteristics of gas gap between heating electrode and substrate is a key factor affecting thermal characteristics of MHP. Using standard CMOS technology and simple post-CMOS process,a MHP with sectional area of 35 μm × 35 μm and thickness of 550 nm air gap is designed. Using self-heating effect of MHP,thermal conductance of gas gap is measured in thermal steady state.The results show that gas gap conductance is 6. 74 × 10^-5W / Km and the overall conductance is 7. 51 × 10^-5W /Km,which indicates that gas gap conductance dominates the heat loss of MHP.