A Study to Enhance the Sensing Properties of Ion- Sensitive Field-Effect Transistor

• Main Authors: Yu-Hao Chang, 張育豪
• Other Authors: Chih-Ting Lin
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/9rpaad

碩士 === 國立臺灣大學 === 生醫電子與資訊學研究所 === 107 === As a widely-discussed chemo- and bio-sensor, Ion-Sensitive Field-Effect Transistor is easily to be minilized and be manufactured due to its compatibility to semiconductor fabrication; therefore, it is suitable to be applied in the internet of things(IoT). In this thesis, we target the non-ideal effect, photo effect, and the low sensitivity problem we encountered when we tried to applied the Dual-Gate Ion-Sensitive Field-Effect Transistor(DG-ISFET) to measure the glycated hemoglobin. We attempt to characterize the photo effect phenomenon of DG-ISFET and its mechanism. Besides, we conduct the single-layer graphene transfer post-process trying to enhance the sensitivity of DG-ISFET. The DG-ISFET used in this research was produced and designed by Taiwan Semiconductor Manufacturing Company. In the research of photo effect, we measure the electrical response at different bias to investigate the phenomenon of photo effect. The results imply that the photo effect is obvious only at certain conbinations of solution-gate voltage, back-gate voltage, and drain-to-source voltage. As for the research of single- layer graphen transfer, we compare the Id-Vsg curves before the transfer process and those after the transfer process to analyze the effect of additional graphene layer. By measuring the solution in different pH values and different concentrations of PBS, we found that additional to considering the electrical double layer capacitance of graphene and the quantum capacitance, we also need to take the ion adsorption effect into consideration. By these two, we hope to apply DG-ISFET more in IoT.