HALFGELEIDERINRICHTING, OMVATTENDE EEN HALFGELEIDERLICHAAM MET EEN VEELVOUD VAN GELEIDENDE LAGEN, MET EEN VOORAF BEPAALD PATROON VAN GELEIDERS.

摘要

1308359 Etching FAIRCHILD CAMERA & INSTRUMENT CORP 14 Oct 1970 [31 Oct 1969] 48844/70 Heading B6J [Also in Division H1] In an integrated circuit comprising several mutually insulated superposed metal interconnection layers on a semi-conductor substrate the interconnections in all save the uppermost layer have sloping sides and ends which blend gradually into their upper surfaces so to avoid sudden changes in elevation of subsequently deposited insulating and interconnecting layers. Standard techniques are employed in the manufacture except that the etchant used in patterning deposited metal to form the interconnections is selected so that it gradually undermines the photoresist masking pattern during etching to appropriately contour the interconnections. In the embodiment where the metal is aluminium or aluminium-silicon alloy (less than 2% silicon) a mixture of, by volume, 20% concentrated acetic, 20% concentrated nitric and 60% concentrated prosphoric acids is used as etchant at 85‹ C. The effect of varying the composition and temperature of the acid is discussed.