WAFER THROUGH-HOLE INTERCONNECTIONS WITH HIGH VERTICAL WIRING DENSITIES

A novel wafer through-hole technique with a high vertical wiring densi ty is introduced compatible with standard semiconductor processes. The basic idea is to realize metallic interconnection lines on the inclin ed sidewalls of anisotropically etched through-holes in [100] oriented silicon substrates, The key process is the application of an electrod eposited photoresist capable to cover such complex three-dimensional s tructures, Further, conventional deep ultraviolet light exposure enabl es photolithography on the inclined sidewalls with a good resolution. Interconnections have been achieved with line widths of 20 mu m enabli ng wiring densities up to 250 cm(-1).