Abstract: A heater design for post-process trimming of thin-film transistors is described. The heater incorporates low sheet-resistance material deposited in non-active connecting regions of the heater to reduce heat generation and power consumption in areas distant from active heating members of the heater. The heating members are proximal to a thin-film resistor. The resistance of the thin-film resistor can be trimmed permanently to a desired value by applying short current pulses to the heater. Optimization of a heater design is described. Trimming currents can be as low as 20 mA.