Degree Granting Department
Shekhar Bhansali, Ph.D.
Transition elements, Gold, Diffusion, Resistivity, Resistance
A bulk silicon temperature sensor is fabricated in this work. The objective is to develop a low-cost high resolution temperature sensor. The target applications are a Conductivity-Temperature-Depth (CTD) sensor for oceanic applications and a magnetocaloric microcooler. The properties of silicon are modified by thermal diffusion of gold. Gold is a fast diffuser in silicon and its diffusion contributes to the increase in resistivity of silicon. The addition of gold to n-type silicon creates a negative temperature coefficient device. The effect of the diffusing environment was investigated by diffusing in oxygen and nitrogen ambient at various temperatures. The influence of area of gold diffusion was also investigated. The effect of temperature on resistance was measured and was used to calibrate the sensor.
Although the sensors fabricated in an oxygen environment have an exponential type response, they can be used in the CTD application because of enhanced sensitivity in the 10Ê»C - 30Ê»C temperature range. Sensors fabricated in a nitrogen environment are found to have linear response with sensitivity ranging from 7and#8486;/Ê»C to 3000and#8486;/Ê»C and can be used for both applications. The fabricated sensors have a 0.1Ê»C resolution.
Scholar Commons Citation
Kishanlal Premchand, Bharath Bethala, "Bulk silicon based temperature sensor" (2005). Graduate Theses and Dissertations.