| 摘要 |
PURPOSE:To make thermal radiation excellent without degrading the strength of substrate by a method wherein the grooves are formed on the adhered surface of insulating or semi-insulating semiconductor substrate. CONSTITUTION:The back side of GaAs substrate 2 formed of specified active region by introducing specified impurities by means of epitaxial growth and ion implantation in the surface layer 1 is coated with photoresist film 3. Then said photoresist film 3 is formed into square type pattern by means of well known photolithography. After etching the GaAs substrate 2 utilizing the photo- resist film 4 patterned as shown in the figure as a mask, said photoresist film 4 is removed. As shown in the figure, square projects 5 of specified pattern are formed on the back side of GaAs substrate to form the grooves 6 of specified dimension surrounded by said projects increasing the surface area of the back side of GaAs substrate to make thermal radiation excellent. |
