The study of varies sening layers on Re-FET and ISFET

• Main Author: 黃俊皓
• Other Authors: 張國明
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/72145532031048688485

碩士 === 國立交通大學 === 電子工程系所 === 94 === The ion-sensitive field effect transistors (ISFET) were first presented by P.Bergveld in 1970. They have different materials instead of the general metal/poli-Si gate of traditional MOS. As the unknown solution contacts the sensing material, specific ions would act with the sensing material, therefore, trapped charge lead to a shift on electrical properties. We have measured these changes to determine the degree of the reaction, and then, the concentration of the specific ions should be leveled by analysis the result data. In this thesis, five different materials (HfO2, ZrO2, TiO2, Al2O3, Si3N4 ) are used to be the sensing layers on ISFETs. All the devices fabrications were completed in the clean room (class 10000) of NDL and NFC of NCTU.4 inches p-type wafers were used in these procedures. Each wafer has fourteen devices. Differ to ordinary ISFETs device ,the device in this thesis has symmetrical pattern(i.e. two ISFETs with common source).As all the fabricating step are finished, the performance of these devices were measured and defined in OEM-Lab. The working point of each device was dependent on its ID-VD curve. At this defined working point, the devices were soaked in solutions with different PH value in sequence. ID-VG curves were recorded to define the sensitivity of these ISFETs. In this thesis, the following chapters will describe details on the fabrication process and measure conditions. Also, the property improvement will be discussed. According to the result, some ideas of future work will be mentioned.