A first gate and a second gate are formed on a substrate with a gap between the first and second gates. The first gate has a first sidewall. The second gate has a second sidewall directly facing the first sidewall. A first sidewall spacer is disposed on the first sidewall. A second sidewall spacer is disposed on the second sidewall. A contact etch stop layer is deposited on the first and second gates and on the first and second sidewall spacers. The contact etch stop layer is subjected to a tilt-angle plasma etching process to trim a corner portion of the contact etch stop layer. An inter-layer dielectric layer is then deposited on the contact etch stop layer and into the gap.

A Laterally Diffused Metal Oxide Semiconductor (LDMOS) transistor with implant alignment spacers includes a gate stack comprising a first nitride layer. The first nitride layer is formed on a silicon layer. The gate stack is separated from a substrate by a first oxide layer. The gate stack includes a polysilicon layer formed from the silicon layer, and a second oxide layer is formed on a sidewall of the polysilicon layer. A drain region of the LDMOS transistor is implanted with a first implant aligned to a first edge formed by the second oxide layer. A second nitride layer conformingly covers the second oxide layer. A nitride etch-stop layer conformingly covers the second nitride layer.

A semiconductor device and a method of forming the same are provided. The method includes forming a sacrificial gate structure over an active region. A first spacer layer is formed along sidewalls and a top surface of the sacrificial gate structure. A first protection layer is formed over the first spacer layer. A second spacer layer is formed over the first protection layer. A third spacer layer is formed over the second spacer layer. The sacrificial gate structure is replaced with a replacement gate structure. The second spacer layer is removed to form an air gap between the first protection layer and the third spacer layer.

The present disclosure relates to a semiconductor device including a substrate and a pair of spacers on the substrate. Each spacer of the pair of spacers includes an upper portion having a first width and a lower portion under the upper portion and having a second width different from the first width. The semiconductor device further includes a gate structure between the pair of spacers. The gate structure has an upper gate length and a lower gate length that is different from the upper gate length.

A device includes a semiconductor substrate, a source feature and a drain feature over the semiconductor substrate, a stack of semiconductor layers interposed between the source feature and the drain feature, a gate portion, and an inner spacer of a dielectric material. The gate portion is between two vertically adjacent layers of the stack of semiconductor layers and between the source feature and the drain feature. Moreover, the gate portion has a first sidewall surface and a second sidewall surface opposing the first sidewall surface. The inner spacer is on the first sidewall surface and between the gate portion and the drain feature. The second sidewall surface is in direct contact with the source feature.

A method comprises forming a gate structure over a semiconductor substrate; etching back the gate structure; forming a gate dielectric cap over the etched back gate structure; depositing an etch-resistant layer over the gate dielectric cap; depositing a contact etch stop layer over the gate dielectric cap and an interlayer dielectric (ILD) layer over the contact etch stop layer; performing a first etching process to form a gate contact opening extending through the ILD layer and terminating prior to reaching the etch-resistant layer; performing a second etching process to deepen the gate contact opening, wherein the second etching process etches the etch-resistant layer at a slower etch rate than etching the contact etch stop layer; and forming a gate contact in the deepened gate contact opening.

A semiconductor device structure includes a dielectric layer, a first source/drain feature in contact with the dielectric layer, wherein the first source/drain feature comprises a first sidewall, and a second source/drain feature in contact with the dielectric layer and adjacent to the first source/drain feature, wherein the second source/drain feature comprises a second sidewall. The structure also includes an insulating layer disposed over the dielectric layer and between the first sidewall and the second sidewall, wherein the insulating layer comprises a first surface facing the first sidewall, a second surface facing the second sidewall, a third surface connecting the first surface and the second surface, and a fourth surface opposite the third surface. The structure includes a sealing material disposed between the first sidewall and the first surface, wherein the sealing material, the first sidewall, the first surface, and the dielectric layer are exposed to an air gap.

A method of fabricating a device includes providing a fin having a stack of epitaxial layers including a plurality of semiconductor channel layers interposed by a plurality of dummy layers. A source/drain etch process is performed to remove portions of the stack of epitaxial layers in source/drain regions to form trenches that expose lateral surfaces of the stack of epitaxial layers. A dummy layer recess process is performed to laterally etch the plurality of dummy layers to form recesses along sidewalls of the trenches. An inner spacer material is deposited along sidewalls of the trenches and within the recesses. An inner spacer etch-back process is performed to remove the inner spacer material from the sidewalls of the trenches and to remove a portion of the inner spacer material from within the recesses to form inner spacers having a dish-like region along lateral surfaces of the inner spacers.

A semiconductor structure and a method for preparing a semiconductor structure are provided. The method for preparing the semiconductor structure includes operations as follows. A substrate is provided, and a plurality of gate structures are arranged at intervals on the substrate. A sacrificial sidewall with a preset thickness is formed on a sidewall of the gate structure. A first dielectric layer is formed between adjacent sacrificial sidewalls, a top of the first dielectric layer being flush with a top of the gate structure and a top of the sacrificial sidewalls. The sacrificial sidewall is removed and an air gap structure is formed on the sidewall of the gate structure. A second dielectric layer is formed, the second dielectric layer covering the top of the gate structure, a top opening of the air gap structure and the top of the first dielectric layer.

Provided is a semiconductor device including a substrate, multiple first gate structures, and a protective structure. The substrate includes a first region and a second region. The first gate structures are disposed on the substrate in the first region. The protective structure conformally covers a sidewall of one of the first gate structures adjacent to the second region. The protective structure includes a lower portion and an upper portion disposed on the lower portion. The lower portion and the upper portion have different dielectric materials. A method of forming a semiconductor device is also provided.