A semiconductor device and a method for manufacturing the same are provided. The semiconductor device includes a substrate, a bit line, an isolation spacer, a conductive layer, a landing pad, and an air gap protection structure. The substrate includes a plurality of liners disposed on side surfaces of a trench in the substrate. The bit line is disposed on the substrate. The isolation spacer is disposed on a sidewall of the bit line. The isolation spacer includes an air gap. The conductive layer is disposed over the substrate and next to the isolation spacer. The landing pad is disposed over the bit line. The air gap protection structure covers the landing pad and the air gap. The air gap protection structure includes an upper portion above a top surface of the landing pad and a lower portion below the upper portion.

A semiconductor device and a method for manufacturing the same are provided. The semiconductor device includes a substrate, a bit line, an isolation spacer, a conductive layer, a landing pad, and an air gap protection structure. The substrate includes a plurality of liners disposed on side surfaces of a trench in the substrate. The bit line is disposed on the substrate. The isolation spacer is disposed on a sidewall of the bit line. The isolation spacer includes an air gap. The conductive layer is disposed over the substrate and next to the isolation spacer. The landing pad is disposed over the bit line. The air gap protection structure covers the landing pad and the air gap. The air gap protection structure includes an upper portion above a top surface of the landing pad and a lower portion below the upper portion.

A semiconductor device and a method for manufacturing the same are provided. The semiconductor device includes a substrate, a bit line, an isolation spacer, a conductive layer, a landing pad, and an air gap protection structure. The substrate includes a plurality of liners disposed on side surfaces of a trench in the substrate. The bit line is disposed on the substrate. The isolation spacer is disposed on a sidewall of the bit line. The isolation spacer includes an air gap. The conductive layer is disposed over the substrate and next to the isolation spacer. The landing pad is disposed over the bit line. The air gap protection structure covers the landing pad and the air gap. The air gap protection structure includes an upper portion above a top surface of the landing pad and a lower portion below the upper portion.

A semiconductor device and a method for manufacturing the same are provided. The semiconductor device includes a substrate, a bit line, an isolation spacer, a conductive layer, a landing pad, and an air gap protection structure. The substrate includes a plurality of liners disposed on side surfaces of a trench in the substrate. The bit line is disposed on the substrate. The isolation spacer is disposed on a sidewall of the bit line. The isolation spacer includes an air gap. The conductive layer is disposed over the substrate and next to the isolation spacer. The landing pad is disposed over the bit line. The air gap protection structure covers the landing pad and the air gap. The air gap protection structure includes an upper portion above a top surface of the landing pad and a lower portion below the upper portion.

Embodiments of the present disclosure generally relate to metal gate devices. In one or more embodiments, a method for preparing a device with an airgap is provided and includes depositing a silicon-containing layer on inner surfaces of trenches formed in a metal-gate layer disposed on a substrate, depositing a carbon-containing layer on the silicon-containing layer in the trenches, the carbon-containing layer is deposited to fill at least a lower half of the trenches from the bottom, and leaving a temporary gap within each trench at the top. The method also includes depositing a low-k dielectric layer on the carbon-containing layer and the silicon-containing layer to fill the temporary gap, and exposing at least the carbon-containing layer to a treatment process to remove the carbon-containing layer and form the airgap between the silicon-containing layer and the low-k dielectric layer.

A device includes an active region, a gate structure, a source/drain epitaxial structure, an epitaxial layer, a metal alloy layer, a contact, and a contact etch stop layer. The gate structure is across the active region. The source/drain epitaxial structure is over the active region and adjacent the gate structure. The epitaxial layer is over the source/drain epitaxial structure. The metal alloy layer is over the epitaxial layer. The contact is over the metal alloy layer. The contact etch stop layer lines sidewalls of the source/drain epitaxial structure. The metal alloy layer is spaced apart from the contact etch stop layer.

The present disclosure provides a method of manufacturing a semiconductor device. The method includes forming a first spacer on a bit line, wherein the first spacer includes low-k material doped with carbon. An oxidation process is performed to the first spacer such that a surface portion of the first spacer is transformed to an oxide spacer. The first spacer has a remaining first spacer that is not oxidized by the oxidation process. Then, a second spacer is formed on the oxide spacer, wherein the second spacer includes nitride. The oxide spacer is removed to form a gap between the remaining first spacer and the second spacer. A cover layer is formed to cover the bit line, the remaining first spacer, and the second spacer such that an air gap is sealed by the cover layer, the remaining first spacer, and the second spacer.

A semiconductor device includes a substrate. A gate structure is disposed over the substrate in a vertical direction. The gate structure extends in a first horizontal direction. An air spacer is disposed adjacent to a first portion of the gate structure in a second horizontal direction that is different from the first horizontal direction. The air spacer has a vertical boundary in a cross-sectional side view defined by the vertical direction and the first horizontal direction.

A semiconductor device includes a substrate. A gate structure is disposed over the substrate in a vertical direction. The gate structure extends in a first horizontal direction. An air spacer is disposed adjacent to a first portion of the gate structure in a second horizontal direction that is different from the first horizontal direction. The air spacer has a vertical boundary in a cross-sectional side view defined by the vertical direction and the first horizontal direction.