摘要
采用双槽电化学腐蚀法在p+单晶硅表面制备多孔硅层,然后在多孔硅表面沉积形成Pt薄膜电极,制备出多孔硅气敏元件样品。利用SEM技术分析多孔硅的表面形貌,研究了腐蚀条件对多孔硅的孔隙率、横向I-V特性及低浓度NO2气敏特性的影响。结果表明,多孔硅的横向I-V特性表现出非整流的欧姆接触;多孔硅的孔隙率及其对低浓度NO2的灵敏度均随腐蚀电流密度的增大而增加。当腐蚀电流密度为90 mA/cm2,腐蚀时间为30 min时,所得多孔硅气敏元件对体积分数为200×10-9的NO2的灵敏度可达到5.25,响应时间与恢复时间约分别为14 min与10 min。
Porous silicon （PS） layers have been grown by electrochemical dissolution in a double-tank cell on the surface of the single-crystalline p＋-type silicon. Pt electrodes were deposited on the porous silicon＇s top surfaee to produce electrical contacts for device testing. The surface morphologies of PS layers were characterized by SEM. The inference of etching conditions to the porosity, transverse Ⅰ-Ⅴ characteristics and NO2 gas-sensing properties of PS were thoroughly investigated. It was shown that the transverse Ⅰ-Ⅴ characteristics of the PS gas sensors had nonreetifying properties of ohmic contacts; the porosity and NO2 gas-sensing properties increased with the increased etching current density. The PS gas sensor which was obtained with an etching current density of 90 mA/cm^2 for 30 min shows a high sensitivity of 5. 25 to 200×10^-9 of NO2, and the sensor response and recovery time are sepasately about 14 min and 10 min.
出处
《传感技术学报》
CAS
CSCD
北大核心
2009年第3期316-319,共4页
Chinese Journal of Sensors and Actuators
基金
国家自然科学基金资助项目(60771019,60801018)
关键词
多孔硅
孔隙率
Ⅰ-Ⅴ特性
NO2气敏特性
porous silicon
porosity
Ⅰ-Ⅴ characteristics
NO2 gas-sensing properties
