| 摘要 |
PURPOSE:To coat both surfaces of a wafer with uniform glass passivation films by holding the wafer to a wafer fixing base to which a wafer holding hole, the periphery thereof has a tapered section of a shape that is spot-faced from both surfaces and which is exposed from an insulating coating, is formed and dipping the wafer in an electrodeposition liquid. CONSTITUTION:The wafer to be treated 1 is held between the two wafer fixing bases 21a and 21b, and pushed by electric contact springs 22, 22 at two upper sections and an electric contact spring 23 at a lower position. The upper and lower fixing bases 21a and 21b are combined or separated by inserting spring- shaped guide pins 24 into inserting holes 25. The tapers 26 of the shapes that are spot-faced from both surfaces are formed to the peripheral sections of the holding holes, and sections in width W on the inner peripheral sides of the tapered sections and the contact sections of the electric contact springs 22, 23 are exposed from a Teflon coating 27 functioning as an insulation to the electrodeposition liquid. When the wafer is fitted to such an electrodepositing electrode and electrodeposited, field concentration around the wafer is relaxed on both surfaces, and the thickness of electrodeposited glass films is equalized on both surfaces. |
