Abstract: A method for forming dielectrically isolated devices comprises forming a first insulating layer on a flat monocrystalline surface of a silicon wafer. A plurality of active regions is defined on the surface using existing manufacturing masks. Portions of the insulating layer not included in the device regions are removed, leaving apertures. Silicon is epitaxially deposited within the apertures and over the first insulating layer so as to form a continuous monocrystalline layer. The surface of the monocrystalline is oxidized. The resulting oxide is then removed, thereby exposing the surface of the monocrystalline layer having its thickness reduced. A second insulating layer is formed over the monocrystalline layer, and a layer of silicon nitride is deposited over the second insulating layer. The plurality of active regions is defined on the layer of silicon nitride, again using existing manufacturing masks.

Abstract: A multi-level metallization is formed by forming a patterned first level metallization layer on the surface of an isolating layer on a substrate of semiconductor material. A thick planarizing layer, preferably of a glass, is applied over the first level metallization layer and the exposed areas of the insulating layer with the planarizing layer bearing depressions in its surface over the exposed areas of the insulating layer. A photoresist layer is formed on the planarizing layer in the depressions in its surface with the portions of the planarizing layer over the first level metallization layer being exposed. The exposed areas of the planarizing layer are isotropically etched until the surface of the planarizing layer is substantially planar with the bottom of the deepest depression in the planarizing layer. Any photoresist material is removed and the planarizing layer is isotropically etched until its surface is substantially planar with the surface of the first level metallization layer.