Research and Development of Micro Temperature Sensors

• Main Authors: Ren-Hao Liu, 劉人豪
• Other Authors: Chie Gau
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/16103736088756578462

碩士 === 國立成功大學 === 航空太空工程學系 === 87 === Experiments were conducted to study different concentration effect of either boron or phosphorous implanted into a polysilicon layer and the fabrication of thermal sensors and their calibration. Two different types of thermal sensors, i.e the thermocouple type and the thermal resistance type, were developed and made. Comparison of their performance were also made this thesis.The IC fabrication technologies were used to make the sensor into a 1 cm1 cm semiconductor chip. Both types of sensors were made by implanting different concentration of either boron of phosphorous into polysilicon to change their electric property in order to obtain the best performance. All the fabrication processes were made in NDL. After the fabrication and packaging processes, the sensors were then calibrated in IAA.In the fabrication processes, the dry etching processes was found to be able to make the polysilicon deposited to have a better shape. The implantation coupled with later annealing process can make the concentration of either boron or phosphorous relatively uniform, and the processes can be repeated. From the view point of fabrication process, the fabrication of thermocouple type sensor is more complicated, and needs a reference point. Therefore, more work is needed, such as glue of a copper sheet or tape onto the chip. In addition, it can be readily damaged. When the concentration of the boron or phosphorus implanted into polysilicon is less then 1019 cm-3, the resistance of the polysilicon is still too high to be used as a temperature sensor. For concentration from 1019 cm-3 to 1020 cm-3, the resistance of polysilicon varies clearly with the temperature. In addition, the seebeck coefficient at concentration of 1019 cm-3 has the greatest value. Therefore, implantation of the concentration in the range is suitable for use as thermal sensor. However, implantation of concentration greater then 1020 cm-3 is suitable for use as a heater.