Fig 1. The top view of the on-chip heater or sensor #1 devices.
The chip contains 4 identical resistive elements with 4 electrodes designated for a 4-wire measurement. The resistive element is a temperature sensitive (α = 2.5 × 10−3 °C−1) 40 nm nickel thin film for the sensor or nickel silicide on 500 nm polysilicon for the heater. Both are identically patterned on 500 nm thick silicon nitride membranes. (a) An overview of 2 cm by 1.5 cm chip device. (b) Close-up view of the resistive element pattern on a 500 μm by 500 μm membrane.