公开(公告)号：DE1764951B1

公开(公告)日：1972-03-16

申请号：DE1764951

申请日：1968-09-11

Applicant: IBM

Inventor： EDWARD MUTTER WALTER ,  TOTTA PAUL

IPC: H01L21/00 ,  H01L23/485 ,  H01L23/522 ,  H01L5/14

Abstract: 1,233,466. Semi-conductor devices. INTERNATIONAL BUSINESS MACHINES CORP. 12 Sept., 1968 [15 Sept., 1967], No. 43384/68. Heading H1K. A semi-conductor device comprises a body having a first insulating layer on one surface, a contact stripe making ohmic contact to the body through an aperture in the first insulating layer, a second insulating layer overlying the contact stripe and the first insulating layer and a laminated stripe contacting the contact stripe through an aperture in the second insulating layer, the laminated stripe comprising a layer of copper disposed between two layers of chromium. As shown, Fig. 1, P and N-type regions are produced in an N-type silicon wafer by diffusion or by etching cavities and epitaxially refilling them. A layer 18 of silicon dioxide covers the surface and thin platinum silicide or palladium silicide layers 22 form ohmic contacts to the various regions. Molybdenum or tungsten contact stripes 24 contact the silicide layers and extend on to the surface of the silicon dioxide layer 18. A " glass " layer 20 is provided over the surface and laminar stripes 26 comprising a layer 28 of copper between two layers 27, 29 of chromium contact the contact stripes 24. A second " glass " layer 32 is provided on the surface and laminated contact pads 34, comprising layers 35, 36, 37 of chromium, nickel or copper, and gold respectively, contact laminar stripes 26 and have nickel plated copper balls 38 soldered to them. The lower face of the wafer is provided with a laminated layer 42, comprising a layer 44 of chromium, a layer 46 of nickel or copper and a layer 48 of gold by means of which the device may be soldered to a substrate. The silicon dioxide layer 18 may be applied by RF sputtering or by heating in steam, the first " glass " layer 20 may be applied by RF sputtering, pyrolytic techniques or glass sedimentation followed by fusing, and the second " glass " layer 32 is formed under non-oxidizing conditions, e.g. by RF sputtering. The insulating materials may be inorganic or organic and the term " glass " covers any amorphous inorganic material including silicon nitride, silicon dioxide and silicon monoxide. The metal layers may be applied by evaporation and selective removal. In a second embodiment, Fig. 2 (not shown), the first insulating layer is silicon dioxide or silica, the contact stripes make direct ohmic contact to the device regions and may comprise a layer of silver or gold disposed between two layers of molybdenum or of chromium or may comprise a single layer of molybdenum. The surface is provided with a " glass " layer and second level interconnections of chromiumcopper-chromium, covered with a second glass layer and a third level of interconnections which are covered with a third glass layer provided with laminated contact pads on which are formed solder mounds.