In this paper, an ISFET model is established and its accuracy is verified. The model can overcome the limitation of TCAD of not supporting electrolyte solution simulation. The source and drain of the model structure are doped with different types of impurities. The influence of GaAs as a substrate on the device sensitivity is also studied. Amorphous indium gallium zinc oxide (a-IGZO) material is used as a semiconductor layer to obtain a new type of ISFET with a higher detection sensitivity to the pH value. Furthermore, the addition of SiC material to the new ISFET further improves the device sensitivity. The influence of different oxide layers on the model when GaAs is used as a substrate is also studied. The results show that the new ISFET can not only break through the Nernst limit of the device sensitivity (59 mV pH⁻¹), but also increase the sensitivity by nearly 12 times.

本文建立了一个ISFET模型并验证了其准确性。该模型可以克服TCAD不支持电解质溶液模拟的局限性。模型结构的源极和漏极掺杂了不同类型的杂质。还研究了 GaAs 作为衬底对器件灵敏度的影响。采用非晶铟镓锌氧化物（a-IGZO）材料作为半导体层，获得对pH值具有更高检测灵敏度的新型ISFET。此外，在新型 ISFET 中添加 SiC 材料进一步提高了器件灵敏度。还研究了以 GaAs 为衬底时不同氧化层对模型的影响。结果表明，新型ISFET不仅可以突破器件灵敏度的能斯特极限（59 mV pH ^-1)，还能将灵敏度提高近 12 倍。