A method for forming a doped layer is disclosed. The doped layer may be used in a NMOS or a silicon germanium application. The doped layer may be created using an n-type halide species in a n-type dopant application, for example.

Semiconductor devices and fabrication methods thereof are provided. The method may include forming a first sacrificial film on a to-be-etched layer having; and forming second sacrificial layers on the first sacrificial film. A first trench or a second trench is between adjacent second sacrificial layers; and a width of the second trench is greater than a width of the first trench. The method also includes forming a first sidewall spacer on a sidewall surface of a second sacrificial layer, a ratio between the width of the first trench and a thickness of the first sidewall spacer being greater than 2:1; and etching the first sacrificial film using the first sidewall spacer as an etching mask to form first sacrificial layers. A third trench or a second trench is between adjacent first sacrificial layers. The method also includes forming a second sidewall spacer to fill the third trench.

In a method for forming a semiconductor device, a layer of logic devices is formed on a substrate. The layer of logic devices includes a stack of gate-all-around field-effect transistors (GAA-FETs) positioned over the substrate, where the stack of GAA-FETs includes a first layer of GAA-FETs stacked over a second layer of GAA-FETs. A first wiring layer is formed over the layer of logic devices, where the first wiring layer includes one or more metal routing levels. A memory stack is formed over the first wiring layer. The memory stack includes wordline layers and insulating layers that alternatingly arranged over the first wiring layer. A three-dimensional (3D) NAND memory device is formed in the memory stack. The 3D NAND memory device includes a channel structure that extends into the memory stack and further is coupled to the wordline layers of the memory stack.

A gate structure of a field effect transistor includes a first gate dielectric layer, a second gate dielectric layer, and one or more conductive layers disposed over the first gate dielectric layer and the second gate dielectric layer. The first gate dielectric layer is separated from the second gate dielectric layer by a gap filled with a diffusion blocking layer.

A method includes forming a fin protruding from a semiconductor substrate; forming a dummy gate stack over the fin, wherein forming the dummy gate stack includes depositing a layer of amorphous material over the fin; performing an anneal process on the layer of amorphous material, wherein the anneal process recrystallizes the layer of amorphous material into a layer of polycrystalline material, wherein the anneal process includes heating the layer of amorphous material for less than one millisecond; and patterning the layer of polycrystalline material; and forming an epitaxial source/drain region in the fin adjacent the dummy gate stack; and removing the dummy gate stack and replacing the dummy gate stack with a replacement gate stack.

A method includes forming a semiconductive channel layer on a substrate. A dummy gate is formed on the semiconductive channel layer. Gate spacers are formed on opposite sides of the dummy gate. The dummy gate is removed to form a gate trench between the gate spacers, resulting in the semiconductive channel layer exposed in the gate trench. A semiconductive protection layer is deposited in the gate trench and on the exposed semiconductive channel layer. A top portion of the semiconductive protection layer is oxidized to form an oxidation layer over a remaining portion of the semiconductive protection layer. The oxidation layer is annealed after the top portion of the semiconductive protection layer is oxidized. A gate structure is formed over the semiconductive protection layer and in the gate trench after the oxidation layer is annealed.

A semiconductor device includes a first active region, a second active region spaced apart from the first active region, a plurality of first channel layers disposed on the first active region, and a second channel layer disposed on the second active region. The semiconductor device further includes a first gate structure intersecting the first active region and the first channel layers, a second gate structure intersecting the second active region and the second channel layer, a first source/drain region disposed on the first active region and contacting the plurality of first channel layers, and a second source/drain region and contacting the second channel layer. The plurality of first channel layers includes a first uppermost channel layer and first lower channel layers disposed below the first uppermost channel layer, and the first uppermost channel layer includes a material that is different from a material included in the first lower channel layers.

A method includes depositing an interlayer dielectric (ILD) over a source/drain region, implanting impurities into a portion of the ILD, recessing the portion of the ILD to form a trench, forming spacers on sidewalls of the trench, the spacers including a spacer material, forming a source/drain contact in the trench and removing the spacers and the portion of the ILD with an etching process to form an air-gap, the air-gap disposed under and along sidewalls of the source/drain contact, where the etching process selectively etches the spacer material and the impurity.

A method is provided for sealing a seam in a self-aligned contact (SAC) layer that is disposed on a gate of a semiconductor structure. The method includes depositing a filler in the seam to seal the seam.

A semiconductor device includes a substrate, an isolation structure, a semiconductor fin, a semiconductor layer, and a gate structure. The isolation structure is disposed over the substrate. The semiconductor fin extends from the substrate and in contact with the isolation structure. The semiconductor layer is disposed on and in contact with the isolation structure. The gate structure covers the semiconductor layer and spaced apart from the semiconductor fin.