A ceramic multilayer circuit and a method for manufacturing a ceramic multilayer circuit which has economical, corrosion-resistant external contacts or external conductor paths that are immune to the Kirkendall effect and can be utilized for different mounting processes. The circuit structure and the method involve the use of a pure silver paste to implement external conductor paths or external contacts. Corrosion resistance is ensured by a thin metallic protective layer.
Conductive plugs are formed in a first insulating layer on an integrated circuit substrate. A first conductive layer, a capacitor dielectric film and a second conductive layer are formed on the first insulating layer including on the conductive plugs. The second conductive layer, the capacitor dielectric film and the first conductive layer are patterned to define capacitors, each including a portion of the first conductive layer, a portion of the capacitor dielectric film thereon and a portion of the second conductive layer thereon, and to define a plurality of first conductive layer patterns that are free of the capacitor dielectric film and the second conductive layer thereon. At least a first of the capacitors is electrically connected to a conductive plug and at least a second of the capacitors is not electrically connected to a conductive plug. A second insulating layer is formed on the first insulating layer, on the capacitors and on the first conductive patterns. The second insulating layer includes therein first contact holes that selectively expose the first conductive layer patterns. A first level interconnection is formed in the first contact holes and on the second insulating layer to electrically contact the first conductive patterns and to selectively electrically interconnect selected ones of the first conductive patterns to one another on the second insulating layer. A third insulating layer is formed on the second insulating layer and on the first level interconnection. The third insulating layer includes therein second contact holes that selectively expose the first level interconnection and selected ones of the capacitors. A second level interconnection is formed in the second contact holes and on the third insulating layer to selectively electrically interconnect the at least one of the first capacitors, to selectively electrically contact the first level interconnection and to selectively electrically interconnect selective ones of the at least a second of the capacitors to one another and to the first level interconnection.
Conductive plugs are formed in a first insulating layer on an integrated circuit substrate. A first conductive layer, a capacitor dielectric film and a second conductive layer are formed on the first insulating layer including on the conductive plugs. The second conductive layer, the capacitor dielectric film and the first conductive layer are patterned to define capacitors, each including a portion of the first conductive layer, a portion of the capacitor dielectric film thereon and a portion of the second conductive layer thereon, and to define a plurality of first conductive layer patterns that are free of the capacitor dielectric film and the second conductive layer thereon. At least a first of the capacitors is electrically connected to a conductive plug and at least a second of the capacitors is not electrically connected to a conductive plug. A second insulating layer is formed on the first insulating layer, on the capacitors and on the first conductive patterns. The second insulating layer includes therein first contact holes that selectively expose the first conductive layer patterns. A first level interconnection is formed in the first contact holes and on the second insulating layer to electrically contact the first conductive patterns and to selectively electrically interconnect selected ones of the first conductive patterns to one another on the second insulating layer. A third insulating layer is formed on the second insulating layer and on the first level interconnection. The third insulating layer includes therein second contact holes that selectively expose the first level interconnection and selected ones of the capacitors. A second level interconnection is formed in the second contact holes and on the third insulating layer to selectively electrically interconnect the at least one of the first capacitors, to selectively electrically contact the first level interconnection and to selectively electrically interconnect selective ones of the at least a second of the capacitors to one another and to the first level interconnection.
A low temperature co-fired ceramic assembly (LTCC) with a constraining core to minimize shrinkage of outer ceramic layers during firing. The outer ceramic layers have high density circuit features. A ceramic core includes several ceramic layers. Several via holes are located in the first and second ceramic layers. Several low density circuit features are located on the ceramic layers that make up the core. Outer ceramic layers are placed top and bottom of the ceramic core. The outer ceramic layers have via holes and high density circuit features. The circuit features patterned on the ceramic layers include resistors, capacitors, circuit lines, vias, inductors, or bond pads. The ceramic core is fired first in a furnace. The outer layers are then laminated to the ceramic core and fired. The ceramic core controls the shrinkage rate of the outer ceramic layers during firing allowing higher density circuit features on the outer layers.
A low temperature co-fired ceramic assembly (LTCC) with a constraining core of differing dielectric constants that minimizes shrinkage of the outer ceramic layers during firing. The ceramic assembly has a planar ceramic core. The core has a first ceramic layer with a first dielectric constant and a second ceramic layer adjacent to the first ceramic layer. The second ceramic layer has a second dielectric constant. A third ceramic layer has a third dielectric constant. A fourth ceramic layer has a fourth dielectric constant. The ceramic core is located between the third and the fourth ceramic layers. Several electrically conductive vias extend through the first, second, third and fourth ceramic layers. Several circuit features are located on the first, second, third and fourth ceramic layers. The vias electrically connect the circuit features on the layers.
A wafer includes levels elevated above the wafer substrate or base substrate which includes separated substrates suitable for circuit device element formation. In one embodiment, a first level dielectric is formed over circuit devices having elements formed in the wafer substrate. Contacts from the circuit elements may extend to the surface of the first level dielectric. A second dielectric is formed on the first level dielectric and etched to create separated openings with some openings exposing contacts. The openings are filled with substrate material, thus forming elevated substrates and local interconnects where exposed contact top surfaces are present. The substrate material is suitable for circuit device fabrication. Additional levels of elevated substrates and concurrently formed local interconnects may be subsequently fabricated.