PECVD methods for depositing a film at a low deposition rate comprising intermittent activation of the plasma are disclosed. The flowable film can be deposited using at least a polysilane precursor and a plasma gas. The deposition rate of the disclosed processes may be less than 500 Å/min.

A method of forming a semiconductor device includes: forming a dummy gate structure over a fin structure that protrudes above a substrate, where the fin structure includes a fin and a layer stack over the fin, where the layer stack comprises alternating layers of a first semiconductor material and a second semiconductor material; forming openings in the fin structure on opposing sides of the dummy gate structure, where the openings exposes first portions of the first semiconductor material and second portions of the second semiconductor material; recessing the exposed first portions of the first semiconductor material to form sidewall recesses in the first semiconductor material; lining the sidewall recesses with a first dielectric material; depositing a second dielectric material in the sidewall recesses on the first dielectric material; after depositing the second dielectric material, annealing the second dielectric material; and after the annealing, forming source/drain regions in the openings.

Exemplary methods of forming a silicon-and-carbon-containing material may include flowing a silicon-and-carbon-containing precursor into a processing region of a semiconductor processing chamber. A substrate may be housed within the processing region of the semiconductor processing chamber. The methods may include forming a plasma within the processing region of the silicon-and-carbon-containing precursor. The plasma may be formed at a frequency above 15 MHz. The methods may include depositing a silicon-and-carbon-containing material on the substrate. The silicon-and-carbon-containing material as-deposited may be characterized by a dielectric constant below or about 3.0.

Provided are methods and systems for providing silicon-containing films. The composition of the silicon-containing film can be controlled by the choice of the combination of precursors and the ratio of flow rates between the precursors. The silicon-containing films can be deposited on a substrate by flowing two different organo-silicon precursors to mix together in a reaction chamber. The organo-silicon precursors react with one or more radicals in a substantially low energy state to form the silicon-containing film. The one or more radicals can be formed in a remote plasma source.

Methods for plasma enhanced atomic layer deposition (PEALD) of low-κ films are described. A method of depositing a film comprises exposing a substrate to a silicon precursor having the general formula (I) ##STR00001##
wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are independently selected from hydrogen (H), substituted alkyl, or unsubstituted alkyl; purging the processing chamber of the silicon precursor; exposing the substrate to a carbon monoxide (CO) plasma to form one or more of a silicon oxycarbide (SiOC) or silicon oxycarbonitride (SiOCN) film on the substrate; and purging the processing chamber.

Semiconductor device structures having dielectric features and methods of forming dielectric features are described herein. In some examples, the dielectric features are formed by an ALD process followed by a varying temperature anneal process. The dielectric features can have high density, low carbon concentration, and lower k-value. The dielectric features formed according to the present disclosure has improved resistance against etching chemistry, plasma damage, and physical bombardment in subsequent processes while maintaining a lower k-value for target capacitance efficiency.

Methods for depositing silicon oxycarbide (SiOC) thin films on a substrate in a reaction space are provided. The methods can include at least one plasma enhanced atomic layer deposition (PEALD) cycle including alternately and sequentially contacting the substrate with a silicon precursor that does not comprise nitrogen and a second reactant that does not include oxygen. In some embodiments the methods allow for the deposition of SiOC films having improved acid-based wet etch resistance.

Semiconductor device structures having low-k features and methods of forming low-k features are described herein. Some examples relate to a surface modification layer, which may protect a low-k feature during subsequent processing. Some examples relate to gate spacers that include a low-k feature. Some examples relate to a low-k contact etch stop layer. Example methods are described for forming such features.

A semiconductor device includes a fin protruding from a substrate and extending in a first direction, a gate structure extending on the fin in a second direction, and a seal layer located on the sidewall of the gate structure. A first peak carbon concentration is disposed in the seal layer. A first spacer layer is located on the seal layer. A second peak carbon concentration is disposed in the first spacer layer. A second spacer layer is located on the first spacer layer.

A method for fabricating a semiconductor device includes forming a first wiring layer, the first wiring layer including a first metal wiring and a first interlayer insulating film wrapping the first metal wiring on a substrate, forming a first via layer, the first via layer including a first via that is in electrical connection with the first metal wiring, and a second interlayer insulating film wrapping the first via on the first wiring layer, and forming a second wiring layer, the second wiring layer including a second metal wiring that is in electrical connection with the first via, and a third interlayer insulating film wrapping the second metal wiring on the first via layer, wherein the third interlayer insulating film contains deuterium and is formed through chemical vapor deposition using a first gas containing deuterium and a second gas containing hydrogen.