Abstract: A process is described for electrically interconnecting electronic devices located on a surface through one or more planar linking layers consisting of conductors and dielectrics. A three-step additive process is disclosed for forming each planar linking layer. The process may be repeated in order to form the multiple linking layers required for complex VLSI circuits. Each layer is formed by a three step process of applying a uniform dielectric, removing the dielectric where the interconnections, including vias and lines, are to be made and then selectively depositing a conductor to form the interconnections.

Abstract: An improved method for automatically focusing an integrated circuit manufacturing projection step and repeat photolithography printer employing an optical signal to focus the printer is disclosed. The automatic focusing is achieved by reflecting an optical signal off a photoresist layer on the surface of a wafer and converting the reflected optical signal into an electronic signal employed to focus the printer. According to the preferred embodiment of the present invention, a dye which absorbs light at the wavelength the optical signal is added to the photoresist layer to improve the quality of the reflected optical signal thereby considerably reducing or eliminating focusing errors.