摘要
在表面基模型理论基础上，本文研究了含两种表面基的Ｓｉ３Ｎ４绝缘体材料及其两种表面基（硅醇基和胺基）的比例系数对ｐＨ－ＩＳＦＥＴ器件敏感特性的影响．在硅醇基／胺基＝７／３附近时，得到电解液一绝缘体（Ｅ－Ｉ）界面势对ｐＨ值的灵敏度最大，且线性响应范围宽；两种表面基的总数密度及其比值的稳定程度直接影响ｐＨ－ＩＳＦＥＴ器件的敏感响应和稳定特性．理论结果与实验观测结果相符，为进一步探索提高ｐＨ－ＩＳＦＥＴ传感器敏感特性的方法提供理论依据．
Abstract Based on the site-binding model, the effect of two kinds of surface-sites (namely,silanol site and amine site)and their ratio on sensitive characteristic of Si3N4-gate pH-ISFET are studied.As the ratio of silanol sites to amine sites is about 7/3,namely,the silanol site is in the range of 60～80 per cent out of the total sites,the maxmium of sensitivity of electrolyte-insulator(E-I)interfacial potential versus pH value,as well as of the range of linear response are theoretically obtained. The stability of pH-ISFET devices is determined by the total mumber of two types of surface-sites and their ratio. The theoretical results correspond with experimental results,which provides guidance for improving sensitive characteristic of pH--ISFET sensors.
关键词
氮化硅
绝缘栅
表面基模型
pH-ISFET器件
Gates (transistor)
Mathematical models
Semiconducting silicon compounds
Silicon nitride
