Multiple Lateral Polysilicon Diodes as Temperature Sensors for Chemical Microreaction Systems

Abstract

Lateral polysilicon P+–N–N+ and P+–P–N+ diodes were fabricated and their reverse current was measured at various temperatures in the range of 50°C to 150°C. The reverse current at a constant bias was characterized and used as a parameter to determine temperature by a method proposed in this work for possible application in a chemical microreaction system. Polysilicon diodes in a series combination of 2 or 3 were also fabricated and their electronic properties such as ON resistance, reverse current and ideality factor were studied. The ON resistance and the ideality factor increased linearly with the number of diodes in series, owing to the effect of the series combination of diodes. The multiple diodes also showed a lower reverse current than the individual single diodes in the series. Hence, it is beneficial to use these multiple diodes as temperature sensors, since they give the least error in temperature determination.