用于MEMS封装的纳米多孔硅气敏特性分析  

Analysis of Gas Sensing Properties of the Nano Porous Silicon for MEMS Packaging

作　　者：许高斌[1] 杨业汕 马渊明[1] 陈兴[1] 

机构地区：[1]合肥工业大学电子科学与应用物理学院安徽省MEMS工程技术研究中心,合肥230009

出　　处：《微纳电子技术》2014年第2期89-93,共5页Micronanoelectronic Technology

基　　金：国家高技术研究发展计划(863计划)资助项目(2013AA041101);安徽省科技攻关计划项目(10120106005)

摘　　要：摘要：采用双槽（自制）电化学腐蚀法在P型单晶硅表面制备多孔硅（PS）层，利用AFM技术分析多孔硅的表面形貌。研究分析了电流密度为20～60mA／cm2时，多孔硅的孔径、孔深和孔隙率，并分析测试了多孔硅对高浓度乙醇的气敏特性。结果表明，在不同的电流密度腐蚀下，孔径都在10nm左右；随着电流密度的增加，多孔硅的孔深和孔隙率增大且腐蚀的均匀性较好。当电流密度大于40mA／cm2后，腐蚀的均匀性开始变差，灵敏度波动较大。通过对多孔硅气体吸附灵敏度的分析，在电流密度为40mA／cm^2时，对各浓度的乙醇气体的灵敏度相对稳定，均值达到2．24X10^6kΩ，因此该类样品更适用于MEMS高真空封装的纳米吸气剂。Abstract： The porous silicon （PS） layers were formed by the electrochemical etching method using the home-made double-tank setup on the surface of the p-type monocrystalline silicon. The surface morphologies of the PS layers were analyzed by the AFM technology. The pore diameter, pore depth and porosity of the PS were analyzed at the current density of 20 - 60 mA/em2 , and the gas sensing properties of the PS were analyzed and tested by the high concentrate ethyl alco- hol. The results show that the pore diameter is all about 10 nm at different corrosion current den- sities. The pore depth and the porosity ty, and the etching uniformity is better. of the PS increase with the increase of the current densi While the current density is more than 40 mA/cm2 , the etching uniformity begins to deteriorate and the fluctuation of the sensitivity is greater. By the analysis of the gas adsorption sensitivity for the PS, the sensitivities of different concentration ethanol gases are relatively stable, and the average value reaches 2.24 × 106 kΩ when the current density is 40 mA/cm2. Thus, the sample is more suitable for the nanogetters of the MEMS high vacuum packaging.

关 键 词：多孔硅(PS) 纳米吸气剂 电化学腐蚀法 气敏特性 灵敏度 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TB33[自动化与计算机技术—控制科学与工程]