Parasitic transistor formation under a semiconductor containing nanosheet device is eliminated by forming an airgap between the source/drain regions of the semiconductor containing nanosheet device and the semiconductor substrate. The airgap is created by forming a sacrificial germanium-containing semiconductor material at the bottom of the source/drain regions prior to the epitaxial growth of the source/drain regions from physically exposed sidewalls of each semiconductor channel material nanosheet of a nanosheet material stack. After inner dielectric spacer formation, the sacrificial germanium-containing semiconductor material can be reflown to seal any possible openings to the semiconductor substrate. The source/drain regions are then epitaxially grown and thereafter, the sacrificial germanium-containing semiconductor material is removed from the structure creating the airgap between the source/drain regions of the semiconductor containing nanosheet device and the semiconductor substrate.

The present disclosure describes a fabrication method that can form air-gaps in shallow trench isolation structures (STI) structures. For example, the method includes patterning a semiconductor layer over a substrate to form semiconductor islands and oxidizing the sidewall surfaces of the semiconductor islands to form first liners on the sidewall surfaces. Further, the method includes depositing a second liner over the first liners and the substrate and depositing a first dielectric layer between the semiconductor islands. The second liner between the first dielectric layer and the first liners is removed to form openings between the first dielectric layer and the first liners. A second dielectric layer is deposited over the first dielectric layer to enclose the openings and form air-gaps between the first dielectric layer and the first liners so that the gaps are positioned along the first liners.

The present disclosure describes a fabrication method that can form air-gaps in shallow trench isolation structures (STI) structures. For example, the method includes patterning a semiconductor layer over a substrate to form semiconductor islands and oxidizing the sidewall surfaces of the semiconductor islands to form first liners on the sidewall surfaces. Further, the method includes depositing a second liner over the first liners and the substrate and depositing a first dielectric layer between the semiconductor islands. The second liner between the first dielectric layer and the first liners is removed to form openings between the first dielectric layer and the first liners. A second dielectric layer is deposited over the first dielectric layer to enclose the openings and form air-gaps between the first dielectric layer and the first liners so that the gaps are positioned along the first liners.

An integrated circuit may be formed by forming a buried isolation layer in an isolation recess in a single-crystal silicon-based substrate. Exposed lateral surfaces of the substrate at the buried isolation layer are covered with a dielectric sidewall. A seed trench is formed through the buried isolation layer to expose the substrate. A single-crystal silicon-based seed layer is formed through the seed trench, extending above the top surface of the buried isolation layer. A silicon-based non-crystalline layer is formed contacting the seed layer. A cap layer is formed over the non-crystalline layer. A radiant-induced recrystallization process converts the non-crystalline layer to a single-crystal layer aligned with the seed layer. The cap layer is removed and the single-crystal layer is planarized, leaving an isolated semiconductor layer over the buried isolation layer.

Techniques are disclosed for forming integrated circuit structures having a plurality of non-planar transistors. An insulation structure is provided between channel, source, and drain regions of neighboring fins. The insulation structure is formed during back side processing, wherein at least a first portion of the isolation material between adjacent fins is recessed to expose a sub-channel portion of the semiconductor fins. A spacer material is then deposited at least on the exposed opposing sidewalls of the exposed sub-channel portion of each fin. The isolation material is then further recessed to form an air gap between gate, source, and drain regions of neighboring fins. The air gap electrically isolates the source/drain regions of one fin from the source/drain regions of an adjacent fin, and likewise isolates the gate region of the one fin from the gate region of the adjacent fin. The air gap can be filled with a dielectric material.

The present disclosure provides a semiconductor structure and a manufacturing method for the semiconductor structure. The semiconductor structure manufactured according to the manufacturing method provided in the present disclosure comprises a substrate and a gate formed on the substrate, and a silicon epitaxial layer is formed on the substrate at two sides of the gate; and a side surface of the gate is provided with a first side wall, with a gap being provided between the first side wall and the silicon epitaxial layer, and a surface of the first side wall further comprises a second side wall, with the second side wall covering the gap, so that there is an air gap between the first side wall and the silicon epitaxial layer.

In one embodiment of the present invention, an electronic device includes a first emitter/collector region and a second emitter/collector region disposed in a substrate. The first emitter/collector region has a first edge/tip, and the second emitter/collector region has a second edge/tip. A gap separates the first edge/tip from the second edge/tip. The first emitter/collector region, the second emitter/collector region, and the gap form a field emission device.

A method of forming semiconductor memory device includes the following steps. Firstly, a substrate is provided and the substrate includes a cell region. Then, plural bit lines are disposed within the cell region along a first direction, with each of the bit line includes a tri-layered spacer structure disposed at two sides thereof. Next, plural of first plugs are formed within the cell region, with the first plugs being disposed at two sides of each bit lines. Furthermore, plural conductive patterns are formed in alignment with each first plugs. Following theses, a chemical reaction process is performed to modify the material of a middle layer of the tri-layered spacer structure, and a heat treatment process is performed then to remove the modified middle layer, thereto form an air gap layer within the tri-layered spacer structure.

A semiconductor structure includes a substrate, at least one first gate structure, at least one first spacer, at least one source drain structure, and a conductive plug. The first gate structure is present on the substrate. The first spacer is present on at least one sidewall of the first gate structure. The source drain structure is present adjacent to the first spacer. The conductive plug is electrically connected to the source drain structure while leaving a gap between the conductive plug and the spacer.

Techniques are disclosed for forming integrated circuit structures having a plurality of non-planar transistors. An insulation structure is provided between channel, source, and drain regions of neighboring fins. The insulation structure is formed during back side processing, wherein at least a first portion of the isolation material between adjacent fins is recessed to expose a sub-channel portion of the semiconductor fins. A spacer material is then deposited at least on the exposed opposing sidewalls of the exposed sub-channel portion of each fin. The isolation material is then further recessed to form an air gap between gate, source, and drain regions of neighboring fins. The air gap electrically isolates the source/drain regions of one fin from the source/drain regions of an adjacent fin, and likewise isolates the gate region of the one fin from the gate region of the adjacent fin. The air gap can be filled with a dielectric material.