Abstract: A method of making a bipolar transistor includes forming a stack of a first, second, third and fourth insulating layers on a substrate. An opening is formed in the stack to reach the substrate. An epitaxial process forms the collector of the transistor on the substrate and selectively etches an annular opening in the third layer. The intrinsic part of the base is then formed by epitaxy on the collector, with the intrinsic part being separated from the third layer by the annular opening. The junction between the collector and the intrinsic part of the base is surrounded by the second layer. The emitter is formed on the intrinsic part and the third layer is removed. A selective deposition of a semiconductor layer on the second layer and in direct contact with the intrinsic part forms the extrinsic part of the base.

Abstract: A method of making a bipolar transistor includes forming a stack of a first, second, third and fourth insulating layers on a substrate. An opening is formed in the stack to reach the substrate. An epitaxial process forms the collector of the transistor on the substrate and selectively etches an annular opening in the third layer. The intrinsic part of the base is then formed by epitaxy on the collector, with the intrinsic part being separated from the third layer by the annular opening. The junction between the collector and the intrinsic part of the base is surrounded by the second layer. The emitter is formed on the intrinsic part and the third layer is removed. A selective deposition of a semiconductor layer on the second layer and in direct contact with the intrinsic part forms the extrinsic part of the base.

Abstract: A method of fabrication of an integrated circuit is provided, including: providing a substrate including a first active layer and a first metallic level of interconnection arranged on top of the active layer and including first lines of interconnection separated by a first filling of sacrificial material; forming a superposition of an insulator layer and second lines of interconnection; providing access to the first filling through the insulator layer; filling the provided access with a second filling of sacrificial material; forming a second active layer on top of the second metallic level of interconnection; providing access to the second filling through the second active layer; and removing the first and the second fillings by a chemical etching through the provided access to the second filling.

Abstract: A bipolar transistor is supported by a single-crystal silicon substrate including a collector contact region. A cyclical epitaxy process is performed to provide a collector region of a first conductivity type on the collector contact region that is laterally separated from a silicon layer by an air gap. A second epitaxial region forms a base region of a second conductivity type. Deposited semiconductor material forms an emitter region of the first conductivity type. The collector region, base region and emitter region are located within an opening formed in a stack of insulating layers that includes a sacrificial layer. The sacrificial layer is selectively removed to expose a side wall of the base region. Epitaxial growth from the exposed sidewall forms a base contact region.

Abstract: A method of fabrication of an integrated circuit is provided, including: providing a substrate including a first active layer and a first metallic level of interconnection arranged on top of the active layer and including first lines of interconnection separated by a first filling of sacrificial material; forming a superposition of an insulator layer and second lines of interconnection; providing access to the first filling through the insulator layer; filling the provided access with a second filling of sacrificial material; forming a second active layer on top of the second metallic level of interconnection; providing access to the second filling through the second active layer; and removing the first and the second fillings by a chemical etching through the provided access to the second filling.

Abstract: Method of making an integrated circuit, comprising at least the following steps: a) form a first semiconducting or conducting element, covered with a first insulating layer on which there is a second semiconducting or conducting element, covered with a second insulating layer; b) form an opening passing through at least the second insulating layer, exposing a portion of the second element and opening up at least partly on the second element or adjacent to the second element; c) form a spacer located at the second element and comprising at least one dielectric material located at least between the second element and the opening; d) prolong the opening through the first insulating layer as far as the first element; and e) fill the opening with at least one conducting material, so as to form a contact. FIG 1G.