Instability and dynamics of thermal runaway of thermoresistive microsensors

Under specific biasing conditions the characteristics of thermoresistive sensors become nonlinear. A significant feature is the appearance of thermal runaway. In this paper, the conditions of appearance and the dynamics of this phenomenon have been evaluated by simulations and by experiments. The origin of thermal instability is electrothermal feedback and results from sensor biasing. Under the condition of negative electrothermal feedback the sensor response is faster, while for destructive positive feedback, response times and sensor temperature increase to large values that exceed the range of practical use.