Preheated cw laser annealed transistors in silicon on sapphire

p-channel metal-oxide-semiconductor transistors have been fabricated in silicon on sapphire. The electrical properties of cw laser annealed transistors which had been subjected to a low-temperature annealing before the laser annealing treatment, were found to be superior to laser annealed transistors and to furnace annealed transistors. The new annealing processes prevent the formation of the defect centers which normally after laser annealing have a degrading influence on the carrier mobility of the material. The defect concentration was measured by deep level transient spectroscopy.