Abstract: A process for creating BPSG filled, shallow trench isolation regions, in a semiconductor substrate, has been developed. The process features the use of a BPSG layer with about 4 to 4.5 weight percent B.sub.2 O.sub.3, and about 4 to 4.5 weight percent P.sub.2 O.sub.5, in silicon oxide. This BPSG composition, when subjected to a high temperature anneal procedure, results in softening, or reflowing, of the BPSG layer, eliminating seams or voids, in the BPSG layer, that may have been present after BPSG deposition. The removal rate of BPSG, is lower than the removal rate of silicon oxide layer, in buffered HF solutions, thus allowing several buffered HF procedures to be performed without recessing of BPSG in the shallow trench. In addition this composition of BPSG performs as a gettering material for mobile ions, thus contributing to yield and reliability improvements, when used at the isolation region for MOSFET devices.

Abstract: A semiconductor fabrication method is provided for the fabrication of a shallow-trench isolation (STI) structure in integrated circuit. Conventionally, the insulating plug of the STI structure would be undesirably formed with microscratches in its top surface resulting from chemical-mechanical polishing (CMP) process, thus causing an undesired bridging effect thereacross when conductive layers are subsequently formed. This method can help solve this problem by forming a mending dielectric layer over the insulating plug of the STI structure to mend these microscratches. Since the mending dielectric layer is in a flowable state when it is being coated over the wafer, it can fill up all the microscratches in the top surface of the insulating plug, thereby mending the microscratches to prevent the bridging effect across the insulating plug that would other-wise occur in the case of the prior art.

Abstract: A method is described for forming MOSFETs with shallow trench isolation wherein the abrupt corners introduced by anisotropically etching the silicon trenches are modified by an oxidation step which rounds off the corners and also reduces the effect of tensile stresses caused by the densified trench filler material. The method selectively exposes the corner regions to an oxidation whereby the formation of an oxide birdsbeak modulates the corners and introduces a compressive stress component in the corner region. Several variations of the procedure are disclosed, including embodiments wherein birdsbeaks extending in both a vertical and horizontal directions from the corners are employed. The channel and gate oxide edges of MOSFETs extend to these corners. By attenuating the abrupt corners and reducing the mechanical stresses, gate oxide integrity is improved and anomalous sub-threshold currents of MOSFETs formed are abated.

Abstract: On a semiconductor substrate are successively deposited a silicon dioxide film and a silicon nitride film. The silicon nitride film, the silicon dioxide film, and the semiconductor substrate are sequentially etched using a photoresist film with an opening corresponding to an isolation region, thereby forming a trench. After depositing a diffusion preventing film, there is deposited an insulating film for isolation having reflowability. Although a void is formed in the insulating film for isolation in the isolation region, the insulating film for isolation is caused to reflow, thereby eliminating the void. After that, the whole substrate is planarized by CMP so as to remove the silicon nitride film and the silicon dioxide film, followed by the formation of gate insulating films, gate electrodes, sidewalls, and source/drain regions in respective element formation regions.

Abstract: The first trench is formed in the region of the semiconductor substrate, in which an element isolation region is to be formed, and the first buried member, which is insulative, is buried in the first trench. Then, the second trench, having a width smaller than that of the first trench, is made in the first buried member, and the portion of the semiconductor substrate which is located at the bottom portion of the first trench, and the insulating second buried member is buried in the second trench, thereby forming the element isolation region.

Abstract: A method for forming a microelectronic structure includes the steps of forming a trench in a substrate and forming an insulating layer which fills the trench and covers the substrate. Ions can be implanted into the insulating layer which decrease an etch rate of the insulating layer, and portions of the insulating layer on the substrate can be removed while maintaining the insulating layer in the trench. In addition, the step of forming the insulating layer can include forming an undoped oxide layer on the substrate and forming a doped oxide layer on the undoped oxide layer wherein a void is formed in the doped oxide layer. The void can thus be reduced by reflowing the doped oxide layer.

Abstract: A body is provided with a substantially horizontal surface and a substantially vertical surface. A film is formed on the body with a substantially horizontal portion on the substantially horizontal surface, a substantially vertical portion on the substantially vertical surface, and a corner region joining the substantially horizontal and substantially vertical portions. The corner region and the substantially vertical portion of the film are removed while the body and the substantially horizontal portion of the film are left substantially intact. A high density plasma with a fluorocarbon-based etching gas may be used to remove the vertical portion and corner region.

Abstract: The semiconductor device includes in a semiconductor substrate (1) at least one predetermined region (6) of the substrate intended subsequently to form an active area, uncovered on its upper surface and situated between lateral trenches (7) containing an insulative material including a layer (9) of a planarising first oxide and at least one underlying layer (8) of a conformal second oxide. The insulative material can form on either side of said uncovered predetermined region (6) of the substrate a boss (16) on the plane upper surface of the device (D) less than 1000 .ANG. high.