A method includes forming a semiconductor fin protruding higher than top surfaces of isolation regions. The isolation regions extend into a semiconductor substrate. The method further includes etching a portion of the semiconductor fin to form a trench, filling the trench with a first dielectric material, wherein the first dielectric material has a first bandgap, and performing a recessing process to recess the first dielectric material. A recess is formed between opposing portions of the isolation regions. The recess is filled with a second dielectric material. The first dielectric material and the second dielectric material in combination form an additional isolation region. The second dielectric material has a second bandgap smaller than the first bandgap.

A method includes forming a semiconductor fin protruding higher than top surfaces of isolation regions. The isolation regions extend into a semiconductor substrate. The method further includes etching a portion of the semiconductor fin to form a trench, filling the trench with a first dielectric material, wherein the first dielectric material has a first bandgap, and performing a recessing process to recess the first dielectric material. A recess is formed between opposing portions of the isolation regions. The recess is filled with a second dielectric material. The first dielectric material and the second dielectric material in combination form an additional isolation region. The second dielectric material has a second bandgap smaller than the first bandgap.

A semiconductor device according to the present disclosure includes a first source/drain feature, a second source/drain feature, a third source/drain feature, a first dummy fin disposed between the first source/drain feature and the second source/drain feature along a direction to isolate the first source/drain feature from the second source/drain feature, and a second dummy fin disposed between the second source/drain feature and the third source/drain feature along the direction to isolate the second source/drain feature from the third source/drain feature. The first dummy fin includes an outer dielectric layer, an inner dielectric layer over the outer dielectric layer, and a first capping layer disposed over the outer dielectric layer and the inner dielectric layer. The second dummy fin includes a base portion and a second capping layer disposed over the base portion.

A semiconductor device according to the present disclosure includes a first source/drain feature, a second source/drain feature, a third source/drain feature, a first dummy fin disposed between the first source/drain feature and the second source/drain feature along a direction to isolate the first source/drain feature from the second source/drain feature, and a second dummy fin disposed between the second source/drain feature and the third source/drain feature along the direction to isolate the second source/drain feature from the third source/drain feature. The first dummy fin includes an outer dielectric layer, an inner dielectric layer over the outer dielectric layer, and a first capping layer disposed over the outer dielectric layer and the inner dielectric layer. The second dummy fin includes a base portion and a second capping layer disposed over the base portion.

A gas sensing device, comprising a bulk and an array of gas sensing elements that are thermally isolated from the bulk, wherein each gas sensing element of a plurality of gas sensing elements of the array comprises (i) a gas reactive element that has a gas dependent temperature parameter; (ii) a semiconductor temperature sensing element that is thermally coupled to the gas reactive element and is configured to generate detection signals that are responsive to a temperature of the gas reactive element; and (iii) multiple heating elements that are configured to heat the gas reactive element to at least one predefined temperature.

A gas sensing device, comprising a bulk and an array of gas sensing elements that are thermally isolated from the bulk, wherein each gas sensing element of a plurality of gas sensing elements of the array comprises (i) a gas reactive element that has a gas dependent temperature parameter; (ii) a semiconductor temperature sensing element that is thermally coupled to the gas reactive element and is configured to generate detection signals that are responsive to a temperature of the gas reactive element; and (iii) multiple heating elements that are configured to heat the gas reactive element to at least one predefined temperature.

In some embodiments, the present disclosure relates to a method for forming an integrated chip (IC), including forming a plurality of image sensing elements including a first doping type within a substrate, performing a first removal process to form deep trenches within the substrate, the deep trenches separating the plurality of image sensing elements from one another, performing an epitaxial growth process to form an isolation epitaxial precursor including a first material within the deep trenches and to form a light absorbing layer including a second material different than the first material within the deep trenches and between sidewalls of the isolation epitaxial precursor, performing a dopant activation process on the light absorbing layer and the isolation epitaxial precursor to form a doped isolation layer including a second doping type opposite the first doping type, and filling remaining portions of the deep trenches with an isolation filler structure.

Embodiments of the invention include a microelectronic device that includes a substrate, at least one dielectric layer on the substrate and a plurality of conductive lines within the at least one dielectric layer. The microelectronic device also includes an air gap structure that is located below two or more of the plurality of conductive lines.

Embodiments of the invention include a microelectronic device that includes a substrate, at least one dielectric layer on the substrate and a plurality of conductive lines within the at least one dielectric layer. The microelectronic device also includes an air gap structure that is located below two or more of the plurality of conductive lines.

A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, an array of memory opening fill structures located within an array of memory openings vertically extending through the alternating stack, and a drain-select-level isolation structure vertically extending through drain-select-level electrically conductive layers between two rows of memory opening fill structures. The drain-select-level isolation structure may comprise a low-k dielectric material or an air gap.