| 摘要 |
PURPOSE:To eliminate etching differences between wafer circumference portion and wafer center portion by a method wherein a etching treatment is executed while semiconductor wafers are held vertically, and one portion thereof is doped in an etching liquid and turned. CONSTITUTION:A wafer 4 is held vertically on a rotary shaft 7, a power is designed to transmit to a rotary shaft 7 from a motor 9 through a rotary transmitting portion 8. The etching is performed while about 2/3 of the wafer 4 is doped in an etching liquid and turned. At this process, in the case the wafer 4 is etched by the normal method, the center portion will become thicker and edge portion will be thinner, whereas using this method the wafer can be uniformly formed in the thickness since the time the center portion doped in the liquid becomes longer. In what degree the wafer should be doped in the etching liquid 2 can be adjusted depend upon the irreguluvity of the thickness of wafers. |
