| 摘要 |
PURPOSE:To contrive the improvement in quality and yield by effecting the nitriding of a GaAs substrate by using a radical produced by decomposing an NH3 gas. CONSTITUTION:A GaAs substrate is irradiated with the ultraviolet rays of wavelength 2,800Angstrom or under while it is heated in a pressure-reduced NH3 gas atmosphere thereby decomposition the NH3 gas, and the surface of GaAs substrate is nitrided by the produced radical. The irradiation of NH3 gas with the ultraviolet rays of wavelength about 1,900Angstrom brings the most efficient photolysis and accordingly if the GaAs substrate is heated in advance, the nitriding progresses easily and the surface of substrate can be changed into GaN. For a light source for generating an ultraviolet ray of wavelength 2,800Angstrom or under, there are a low-pressure mercury lamp, an excimer laser and etc., and argon fluorine excimer laser is most suitable for the light source because the oscillation wavelength is 1,930Angstrom which is in accordance with a peak of light adsorption of NH3 and the average output of 10W or more can be obtained. |
