Evenson, McKeown, Edwards & Lenahan, P.L.L.C.
Method for manufacture of multilayer wiring board and the multilayer wiring board
 In a multilayer wiring board comprising a substrate on which two or more layers of wiring or insulation film are formed of different materials, for example, the wiring layer is processed so that the processed side faces of the board contour a stepped shape in the cross-sectional view of the board, whereby coverage of a film formed thereon can be improved. Specifically, first, insulation film 2 is formed on a substrate 1 and then, resistor film 3 and resistor electrode film 4 are continuously formed thereon to form a film of multiple structure. Mask 9 is formed thereon. Then, the layers is etched successively in the order of from the top layer and thereafter only the resistor electrode film 4 is further etched with an etching solution which selectively etches only the resistor electrode film 4 to form a stepwise patterned side face. Finally, the mask is removed and wiring electrode film 5 is formed. 
Hitachi, Ltd.
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Mitsuru Tetsuya
Usui Watanabe