Heated atomic force microscope cantilever with high resistivity for improved temperature sensitivity

We report a heated atomic force microscope cantilever with a heater region engineered to have high temperature sensitivity. The high resistivity (HR) heater region is phosphorous-doped silicon with a doping concentration of 1 × 10¹⁶ cm^-3 and a resistivity of 0.53 Ω-cm. The heater has a temperature coefficient of resistance of 102 Ω C ^-1 over the temperature range 100-300 C, which is more than one order magnitude higher compared to heated cantilevers from previous publications. When used for thermal sensing of substrate nanotopography, the HR cantilever has a sensitivity of 0.37 mV/nm at 300 C. Because the HR cantilever has high sensitivity at relatively low temperatures, it can be used to measure substrates that cannot withstand high temperatures, demonstrated here as a polymer film grating of thickness 110 nm.