| 摘要 |
PURPOSE:To improve the performance of MOSFET by a method wherein the poly Si gate, the source and the drain are separately annealed using laser under the respective optimum conditions. CONSTITUTION:The field oxide film 2', the gate oxide film 2'' and the P<+> channel cut P'' are provided on the P type Si substrate and the surface is covered with the poly Si 3' and implanted with the B<+> ion to control the threshold level. Next after annealing the surface with the rectangular laser beam L, the poly Si gate electrode 3 is formed by means of patterning while the exposed substrate is covered with the SiO2 2. Then the surface is implanted with the P<+> ion and further radiated by the laser pulse to activate the P<+> ion in the n<+> source, the drain and the poly Si gate. The characteristics of the gate electrode 3 are subject to no change after the two times radiation, because each laser annealing is selectively performed meeting the optimum requirements in terms of respective wavelength, output, waveform and the like. The beams of ion, electron or the like in addn. to laser may be effective. |
