| 摘要 |
PROBLEM TO BE SOLVED: To provide a multilayer interconnection board and a method for forming a multilayer interconnection using it, for forming a multilayer interconnection, even when breakage of resist for forming dot-shaped interconnection metal in the middle layer, which is a problem in micromachining, occurs in a semiconductor multilayer interconnection of three layers or more including a substrate. SOLUTION: On a semiconductor substrate 11 whereupon a transistor area and a upper interconnection are connected by a buried metal 11a on a part of an insulating film, alloy 121 containing aluminum as major component is formed as a first metal layer, a W layer 122 which is not easily etched at the time of etching the aluminum allay is formed on the first metal layer and a resist pattern 13 having a shape of the first interconnection and a resist pattern 13' having a shape of a metal pad are formed. The W film 121 is etched by CF etching gas, then, the aluminum alloy is etched by chlorine etching gas for the aluminum alloy. After removing the remaining resist, forming the interlayer insulating film 14 into a planar form, required areas of the interlayer insulating film are opened and multilayer interconnection is formed. |
