生化微传感集成系统是目前的研究焦点,本文以在线性区和饱和区两种模式下工作的pH-ISFET作为研究对象,提出ISFET微传感器与其信号读出电路的单芯片集成,并深入研究传感机理以及与标准CMOS兼容的敏感材料制备技术.整个芯片包含ISFET/REFET微传感差分对、双模式ISFET/REFET放大器、次级差分放大、参比电极Pt、恒流源等,采用新加坡Chartered半导体集成电路公司3.3V标准CMOS工艺流片.同时进行传感器芯片的pH响应实验测试,获得53mV/pH灵敏度.
Integration of ISFETs in biochemical SOC (System on a Chip) is one of today' s challenges. This article presents a full integration of micro-sensor and readout circuit containing ISFET/REFET (reference PET) pair, ISFET/REFET amplifiers, bias current generator, band-gap reference, as well as a reference electrode structure, all integrated on the same chip based on CMOS technology. The sensor chip is fabricated in a standard 0.35μm CMOS process (Chartered Semiconductor, Singapore) and operates at 3.3V. The extra post processing steps have been developed for ISFEF which can work in either linear or saturation region by programmable control.Finally pH response experiments have been carried out and the measurement system achieves 53 mV/pH sensitivity and the enhanced linearity.