Abstract: A process includes selectively forming laterally adjacent complementary doped epitaxial layers over low resistive buried regions of a horizontally isolated substrate. Self-aligned oxide mask are used for the epitaxial deposition. Lateral dielectric isolation trenches at the complementary doped epitaxial boundary complete the isolation of the islands. Base and emitter regions are formed in the epitaxial collector layers.

Abstract: V-shaped lateral dielectric isolation grooves divide a semiconductor layer into a plurality of regions. The oxide layer above the polycrystalline material in the grooves is thicker than the field oxide layer on the semiconductor layer to prevent the creation of retrograde surface profiles and mask the polycrystalline material during self-aligned device fabrication in the semiconductor layer. The field oxide is formed on the semiconductor layer before the isolation groove fabrication and prevented from increasing in thickness by an oxide inhibiting layer during the isolation groove fabrication.

Abstract: A silicon substrate integrated circuit having a layer of aluminum forming Schottky contacts with lightly doped N conductivity regions and silicon doped aluminum forming ohmic contacts to heavily doped N conductivity regions and forming interconnects between contacts.

Abstract: Fuses and interconnects are fabricated by applying a metallic layer on a substrate and a fusible layer on the metallic layer. Portions of the fusible layer are removed to define discrete fuse elements having a necked portion. Portions of the metallic layer are removed to define interconnects. A portion of the metallic layer coextensive with the necked portion of the fuse elements is removed by selective side etching to form tapering portions separated by a gap without etching of the interconnects. The interconnects are protected from side etching by a separate mask layer or a mask layer used to form the interconnects may be heated to flow down over the sides of the interconnects.

Abstract: A bipolar transistor process and device wherein the transistor is fabricated within a laterally isolated device region, into which is formed a lateral intradevice isolation groove prior to formation of device/active and contact regions. The lateral intradevice isolation groove with the lateral device isolation assists in self-alignment of device regions. The lateral intradevice isolation permits the simultaneous formation through a single mask of an active region and a contact region for a different active region both on the same planar surface of a semiconductor substrate and facilitates extremely close spacing of active regions at the planar surface.

Abstract: V-shaped lateral dielectric isolation grooves divide a semiconductor layer into a plurality of regions. The oxide layer above the polycrystalline material in the grooves is thicker than the field oxide layer on the semiconductor layer to prevent the creation of retrograde surface profiles and mask the polycrystalline material during self-aligned device fabrication in the semiconductor layer. The field oxide is formed on the semiconductor layer before the isolation groove fabrication and prevented from increasing in thickness by an oxide inhibiting layer during the isolation groove fabrication.

Abstract: In a complementary pair of bipolar transistors, one vertical and one lateral, the vertical transistor includes a heavily doped buried emitter, lightly doped buried graded base and a heavily doped surface collector and the lateral transistor includes a lightly doped substrate base and heavily doped emitter and collector. The lateral transistor's collector isolates the lateral transistor's base from the vertical transistor's collector.This integrated circuit approach includes the I.sup.2 L structure of the present invention and T.sup.2 L devices. The I.sup.2 L transistors are in dielectrically isolated regions with the vertical transistors emitter being connected to the polycrystalline support through a vertical opening in the dielectric isolation.

Abstract: In a complementary pair of bipolar transistors, one vertical and one lateral, the vertical transistor includes a heavily doped buried emitter, lightly doped buried graded base and a heavily doped surface collector and the lateral transistor includes a lightly doped substrate base and heavily doped emitter and collector. The lateral transistor's collector isolates the lateral transistor's base from the vertical transistor's collector.This integrated circuit approach includes the I.sup.2 L structure of the present invention and T.sup.2 L devices. The I.sup.2 L transistors are in dielectrically isolated regions with the vertical transistors emitter being connected to the polycrystalline support through a vertical opening in the dielectric isolation.

Abstract: Fuses and interconnects are fabricated by applying a metallic layer on a substrate and a fusible layer on the metallic layer. Portions of the fusible layer are removed to define discrete fuse elements having a necked portion. Portions of the metallic layer are removed to define interconnects. A portion of the metallic layer coextensive with the necked portion of the fuse elements is removed by selective side etching to form tapering portions separated by a gap without etching of the interconnects. The interconnects are protected from side etching by a separate mask layer or a mask layer used to form the interconnects may be heated to flow down over the sides of the interconnects.