- 學位論文
用於生醫感測之陣列式電晶體溫度感測器
CMOS Temperature Sensor Arrays for Biosensing Applications
摘要
本論文旨在以採用CMOS電晶體作為感測元件並建構溫度感測生醫晶片作為研究生化反應時溫度變化與分佈的平台，期利用8×8及16×16溫度感測陣列並搭配數位電路的多工性來驗證及加速在此領域的研究。過去溫度感測器陣列的研發多用於紅外線熱感測，我們所開發晶片也可應用於此方面。 我們所建構的感測機制為使用PMOS電晶體操作在飽和區作溫度感測。由於此時PMOS感測電晶體之電流與溫度變化是成正比關係，故經由所設計之感測電路我們可在輸出端得到與溫度變化相對應之輸出信號。 在電路架構配置方面我們將8×8溫度感測陣列之感測電晶體與電阻加熱器集中排列於晶片中心處，使其與感測電路分開，以得到排列較密的陣列並避免所感測的熱影響到感測電路。所設計之偏壓電路在2D陣列中是每一行感測器共用一組，所需的面積及I/O pad因此可非常精簡。另外在16×16溫度感測陣列方面，則是所有256個感測電晶體皆共用一偏壓電路，更加減少了晶片的面積以及功率消耗。 所建構8×8感測電晶體面積為202 μm × 183 μm而16×16感測電晶體面積為513 μm × 777 μm，感測度為5 mV/1℃，標準差為8.73%，並最小感測度可達0.1℃，經量測後可準確操作在25℃~40℃溫度範圍內。
並列摘要
In this research, we describe the design and characterization of a 8×8 and a 16×16 temperature sensor arrays implemented in a standard CMOS process. The presented construction is based on PMOS transistors operated in saturation region for thermal sensing. Its output level is determined by the sensing PMOS transistor’s saturation current which is proportional to temperature. For the 8×8 sensor array the sensing transistors are placed in the chip center with local polysilicon heaters, preventing other transistors of the sensing circuit from being affected by the temperature variation in the sensors’ area and obtain a more dense arrangement of the sensor array. Also in the 8×8 array, the biasing circuits are shared by every 8 cells, so the chip area could be reduced. In the 16×16 array, all the 256 sensors share one biasing circuit, so the chip area and the power consumption could be more reduced. The 8×8 sensors have an area of 202 μm by 183 μm whereas the 16×16 sensors have an area of 513 μm by 777 μm. The measured resolution is about 5 mV/1℃, whereas the minimum resolution could achieve 0.1℃. The presented temperature sensing could operate accurately over the temperature range 25℃~40℃ with a deviation of 8.73%.