A semiconductor device may include a first active component region (20) and a second active region (22) extending flat along a first lateral direction (L.sub.1) and a second lateral direction (L.sub.2) deviating from said first lateral direction. The semiconductor device may include a trench isolation structure (10, 10′) that electrically isolates the first active component region (20) from the second active region (22) along the first lateral direction (L.sub.1) and comprises at least one electrically conductive sidewall (14, 14′, 14″); said trench isolation structure (10) having a continuously extending insulating trench isolation base wall (30) and a plurality of spaced apart trench isolation portions (32a, 32b) with electrically conductive sidewall portions (14a, 14b) therebetween. The plurality of trench isolation portions (32a, 32b) and the electrically conductive sidewall portions (14a, 14b) are spaced (a, b) from the base wall (30).

The embodiments of mechanisms for doping wells of finFET devices described in this disclosure utilize depositing doped films to dope well regions. The mechanisms enable maintaining low dopant concentration in the channel regions next to the doped well regions. As a result, transistor performance can be greatly improved. The mechanisms involve depositing doped films prior to forming isolation structures for transistors. The dopants in the doped films are used to dope the well regions near fins. The isolation structures are filled with a flowable dielectric material, which is converted to silicon oxide with the usage of microwave anneal. The microwave anneal enables conversion of the flowable dielectric material to silicon oxide without causing dopant diffusion. Additional well implants may be performed to form deep wells. Microwave anneal(s) may be used to anneal defects in the substrate and fins.

In accordance with an embodiment of the present invention, a method of forming a densified fill layer is provided. The method includes forming a pair of adjacent vertical fins on a substrate, forming an inner liner on the sidewalls of the adjacent vertical fins, and forming a sacrificial layer on the inner liner. The method further includes forming a fill layer between the pair of adjacent vertical fins, wherein the fill layer is in contact with at least a portion of the sacrificial layer, removing at least a portion of the sacrificial layer in contact with the fill layer to form sidewall channels adjacent to the fill layer, and subjecting the fill layer to a densification process to form the densified fill layer.

A semiconductor storage device includes: a semiconductor substrate; a plurality of circuit regions; and an element isolation region having a trench shape formed between the circuit regions. In the element isolation region including a thermal oxide film and a silicon oxide film, a sub-trench is formed in a bottom corner portion, and the thermal oxide film covers at least an inner wall of the sub-trench.

A method for forming an isolation structure includes: forming a trench at a surface of a substrate; forming a mask pattern on the substrate, wherein the mask pattern has an opening communicated with the trench; filling a first isolation material layer in the opening and the trench, wherein a surface of the first isolation material layer defines a first recess; filling a second isolation material layer into the first recess; partially removing the first and second isolation material layers, to form a second recess, performing first and second oblique ion implantation processes, to form damage regions in the first isolation material layer; performing a decoupled plasma treatment, to transform portions of the damage regions into a protection layer having etching selectivity with respect to the damage regions; and removing the damage regions.

A semiconductor device has a first trench and a second trench of a trench structure located in a substrate. The second trench is separated from the first trench by a trench space that is less than a first trench width of the first trench and less than a second trench width of the second trench. The trench structure includes a doped sheath having a first conductivity type, contacting and laterally surrounding the first trench and the second trench. The doped sheath extends from the top surface to an isolation layer and from the first trench to the second trench across the trench space. The semiconductor device includes a first region and a second region, both located in the semiconductor layer, having a second, opposite, conductivity type. The first region and the second region are separated by the first trench, the second trench, and the doped sheath.

A method for manufacturing a trench isolation structure comprising forming a shallow trench having a wider upper section and a narrower lower section in a wafer surface, removing part of the silicon oxide by etching, forming a silicon oxide corner structure at a corner at a top corner of the shallow trench by thermal oxidation, depositing silicon nitride on the wafer surface to cover surfaces of the shallow trench silicon oxide and the silicon oxide corner structure, dry etching the silicon nitride on the shallow trench silicon oxide surface thereby forming masking silicon nitride residues extending into the trench, etching downwards to form a deep trench, forming silicon oxide layers on a side wall and the bottom of the deep trench, depositing polycrystalline silicon in the shallow and deep trenches, removing the silicon nitride, and forming silicon oxide in the shallow trench to cover the polycrystalline silicon.

Described examples include a method having steps of forming an isolation pad oxide layer on a substrate and forming and patterning a silicon nitride layer on the isolation pad oxide layer. The method also has steps of oxidizing portions of the substrate not covered by the silicon nitride layer to form a LOCOS layer and oxidizing the silicon nitride layer in an oxidizing ambient containing a chlorine source to form a silicon dioxide layer.

A method for forming a deep trench isolation structure for a CMOS image sensor includes providing a trench that extends from a first side toward a second side of a semiconductor substrate. The trench has an opening on the first side and a bottom and sides. A conformal layer of B-doped oxide is deposited on the bottom and sides of the trench and is less than half a width of the trench leaving a depthwise recess in the trench. A second material is deposited on the conformal layer of B-doped oxide in the trench filling the recess in the trench to the first side. The conformal layer of B-doped oxide is annealed driving boron from the conformal layer of B-doped oxide to the semiconductor substrate forming a B-doped region as a passivation layer juxtaposed next to the conformal layer of B-doped oxide having negative fixed charges.

A process for forming a predetermined separation zone inside a donor substrate, in particular, to be used in a process of transferring a layer onto a carrier substrate comprises an implantation step that is carried out such that the implantation dose in a zone of the edge of the donor substrate is lower than the implantation dose in a central zone of the donor substrate to limit the formation of particles during thermal annealing. The present disclosure also relates to a donor substrate for a process of transferring a thin layer onto a carrier substrate produced by means of the process described above. The present disclosure also relates to a device for limiting an implantation region to a zone of the edge of a donor substrate.