Abstract: An excessive etch in the conventional manufacturing process causes a roughened surface of a contact bottom, resulting in an increased variation in characteristics of semiconductor devices. A bipolar transistor having a collector region 4 provided in a bottom of a trench formed in a P-type silicon substrate 1 is formed. An interlayer insulating film 23 is formed on the P-type silicon substrate 1. The interlayer insulating film 23 above the trench is partially etched to form a portion 30 of an opening for a collector contact. The interlayer insulating film 23 above the trench is partially etched until reaching the bottom thereof to form a residual section 32 of the opening for the collector contact. The residual section 32 of the opening for the collector contact is formed simultaneously with forming an opening 25 for an emitter contact and an opening 27 for a base contact.

Abstract: An excessive etch in the conventional manufacturing process causes a roughened surface of a contact bottom, resulting in an increased variation in characteristics of semiconductor devices. A bipolar transistor having a collector region 4 provided in a bottom of a trench formed in a P-type silicon substrate 1 is formed. An interlayer insulating film 23 is formed on the P-type silicon substrate 1. The interlayer insulating film 23 above the trench is partially etched to form a portion 30 of an opening for a collector contact. The interlayer insulating film 23 above the trench is partially etched until reaching the bottom thereof to form a residual section 32 of the opening for the collector contact. The residual section 32 of the opening for the collector contact is formed simultaneously with forming an opening 25 for an emitter contact and an opening 27 for a base contact.

Abstract: In a method for forming an air gap in an insulating film between adjacent interconnection conductors in a semiconductor device, a substrate having a first insulator film and a plurality of lower level interconnection conductors formed separately from each other on the first insulator film is set in a chemical vapor process machine. A second insulator film is deposited to completely cover the plurality of lower level interconnection conductors and the first insulator film in a chemical vapor process under the condition that a growth speed in a vertical direction perpendicular to a principal surface of the substrate is lower than a growth speed in a horizontal direction in parallel to the principal surface of the substrate, until the second insulator film has such a thickness that an air gap is formed within the second insulator film between the adjacent interconnection conductors.

Abstract: An air structure includes a hollow portion completely embedded within a dielectric layer and between adjacent interconnections that extend over the dielectric layer. The hollow portion has substantially the same shape in plan view as a through hole in the dielectric layer.

Abstract: The present invention provides a method of forming a semiconductor device. The method comprises the following steps. At least a first opening and at least a second opening are concurrently formed in a dielectric layer which has a bottom portion having first level interconnections so that the first and second openings have a bottom level which lies over the first level interconnections. A dielectric film is deposited over the dielectric layer to form an inter-layer insulator so that top portions of the first and second openings are sealed with the dielectric film so as to form at least a first hollow portion and at least a second hollow portion serving as an air gap.