| 摘要 |
PURPOSE:To form even and thin epitaxial layer by only one time anode oxidation by a method wherein an epitaxial layer of semiconductor wafer is anode oxidized while radiating light with specified intensity of illumination to be stopped at specified current density. CONSTITUTION:The quartz vessel 22 in a dark box 21 is filled with specified electrolyte and GaAs epitaxial wafer 24 and Pt electrode 25 are immersed in the electrolyte disposed facing to each other, while epitaxial growth face 24' is radiated with W lamp 26 adjusting anode oxidizing current by means of a resistor 28. The effect of unifying the epitaxial layer is maximized in a dark box diminishing proportionally to the increase of the intensity of illumination, but anode oxidizing the surface of epitaxial layer under radiation of low intensity of illumination while a depletion layer extending from the surface reaches the overall surface of wafer 24 stopping at the same current density on the overall surface. Later removing the oxide film on the epitaxial layer, an even and thin epitaxial layer is formed by only one time anode oxidation. |
