US Patent 8356514 Sensor with improved thermal stability

Improved sensors are disclosed that include a heater resistor and/or one or more sensor resistors. In some instances, the heater resistor may be configured to have a zero or near-zero temperature coefficient of resistance (TCR), while one or more sensor resistors may be configured to have a non-zero higher TCR. In some instances, the heater resistor may include a polysilicon material that is doped with a first concentration of dopant, and the one or more sensing elements may include a polysilicon material that is doped with a second higher concentration of dopant. In some cases, the first concentration of dopant may be configured to provide a heater resistor that has a zero or near-zero temperature coefficient of resistance (TCR).