| 摘要 |
PURPOSE:To provide a uniform, favorable ohmic electrode, by vaporizing a very small quantity of Ag first so as to form nuclei for forming an electrode on a semiconductor wafer for preparing a light emitting diode and subsequently, vaporizing an Au-Zn alloy and further, Au. CONSTITUTION:After a desired degree of vacuum is obtained in a vacuum vessel, Ag 2 is heated by a heater 4 to vaporize Ag by a very small quantity that is enough to form nuclei of Ag on the surface of each wafer 7 to be deposited. After stopping heating of the heater 4, an Au-Zn material 3 is vaporized by heating with the heater 5. When the Au-Zn material 3 is heated, Zn having a high vapor pressure is preferentially deposited on the wafer 7. Flying Zn atoms or particles attach to surroundings of the nuclei and alloy Zn films in the form of islands to grow. With the progress of vaporization of Zn, the whole surface is covered with the Zn films 13. After that, Au is also vaporized and a deposited film 15 of Au-Zn alloy is formed. Au which is left till the end is vaporized and an Au film are formed on the surfaces. |
