Silicon microheaters for local growth of a vertically aligned carbon nanotube (VACNT) were fabricated. The microheaters had a four-point-probe structure that measured the silicon conductivity variations in the heated region which is a measure of the temperature. Through FEM simulations the temperature was determined on the entire microheater structure, and the simulated temperatures were verified by micro-Raman spectroscopy. The microheaters provided a temperature gradient along which VACNTs were grown at 575–800 °C simultaneously. The VACNT growth activation energy was determined to 0.86 eV from the VACNT growth rate variation along the microheater's temperature gradient.