A doped or undoped silicon carbide (SiC.sub.xO.sub.yN.sub.z) film can be deposited in one or more features of a substrate for gapfill. After a first thickness of the doped or undoped silicon carbide film is deposited in the one or more features, the doped or undoped silicon carbide film is exposed to a remote hydrogen plasma under conditions that cause a size of an opening near a top surface of each of the one or more features to increase, where the conditions can be controlled by controlling treatment time, treatment frequency, treatment power, and/or remote plasma gas composition. Operations of depositing additional thicknesses of silicon carbide film and performing a remote hydrogen plasma treatment are repeated to at least substantially fill the one or more features. Various time intervals between deposition and plasma treatment may be added to modulate gapfill performance.

Methods of providing control of film properties during atomic layer deposition using intermittent plasma treatment in-situ are provided herein. Methods include modulating gas flow rate ratios used to generate plasma during intermittent plasma treatment, toggling plasma power, and modulating chamber pressure.

In certain embodiments, a method of processing a semiconductor substrate includes positioning a semiconductor substrate in a plasma chamber of a plasma tool. The semiconductor substrate includes a film stack that includes silicon layers and germanium-containing layers in an alternating stacked arrangement, with at least two silicon layers and at least two germanium-containing layers. The method includes exposing, in a first plasma step executed in the plasma chamber, the film stack to a first plasma. The first plasma is generated from first gases that include nitrogen gas, hydrogen gas, and fluorine gas. The method includes exposing, in a second plasma step executed in the plasma chamber, the film stack to a second plasma. The second plasma is generated from second gases comprising fluorine gas and oxygen gas. The second plasma selectively etches the silicon layers.

A method of forming a semiconductor device includes forming a mask layer over a substrate and forming an opening in the mask layer. A gap-filling material is deposited in the opening. A plasma treatment is performed on the gap-filling material. The height of the gap-filling material is reduced. The mask layer is removed. The substrate is patterned using the gap-filling material as a mask.

Disclosed are methods for etching a silicon-containing film to form a patterned structure, methods for reinforcing and/or strengthening and/or minimizing damage of a patterned mask layer while forming a patterned structure and methods for increasing etch resistance of a patterned mask layer in a process of forming a patterned structure. The methods include using an activated iodine-containing etching compound having the formula C.sub.nH.sub.xF.sub.yI.sub.z, wherein 4≤n≤10, 0≤x≤21, 0≤y≤21, and 1≤z≤4 as an etching gas. The activated iodine-containing etching compound produces iodine ions, which are implanted into the patterned hardmask layer, thereby strengthening the patterned mask layer.

A method for forming a silicon nitride film that may be carbon doped via a plasma ALD process includes introducing a substrate into a reactor, which is heated to up to about 600° C. At least one silicon precursor as defined herein and having one or two Si—C—Si linkages is introduced to form a chemisorbed film on the substrate. The reactor is then purged of any unconsumed precursors and/or reaction by-products with a suitable inert gas. A plasma comprising nitrogen is introduced into the reactor to react with the chemisorbed film to form the silicon nitride film that may be carbon doped. The reactor is again purged of any reaction by-products with a suitable inert gas. The steps are repeated as necessary to bring the deposited silicon nitride film that may be carbon doped to a predetermined thickness.

A method for etching silicon at cryogenic temperatures is provided. The method includes forming an inert layer from condensation of a noble gas at cryogenic temperatures on exposed surfaces such as the sidewalls of a feature to passivate the sidewalls prior to the etching process. The method further includes flowing a fluorine-containing precursor gas into the chamber to form a fluorine-containing layer on the inert layer. The method further includes exposing the fluorine-containing layer and the inert layer to an energy source to form a passivation layer on the exposed portions of the substrate and exposing the substrate to ions to etch the substrate.

A doped or undoped silicon carbide (SiC.sub.xO.sub.yN.sub.z) film can be deposited in one or more features of a substrate for gapfill. After a first thickness of the doped or undoped silicon carbide film is deposited in the one or more features, the doped or undoped silicon carbide film is exposed to a remote hydrogen plasma under conditions that cause a size of an opening near a top surface of each of the one or more features to increase, where the conditions can be controlled by controlling treatment time, treatment frequency, treatment power, and/or remote plasma gas composition. Operations of depositing additional thicknesses of silicon carbide film and performing a remote hydrogen plasma treatment are repeated to at least substantially fill the one or more features. Various time intervals between deposition and plasma treatment may be added to modulate gapfill performance.

A method for forming a silicon dioxide film and a method for forming a metal gate are provided. The method for forming a silicon dioxide film includes: forming a silicon dioxide layer on a semiconductor substrate, performing a nitrogen treatment to the silicon dioxide layer to convert the silicon dioxide layer of partial thickness into a mixed layer of silicon nitride and silicon oxynitride; and removing the mixed layer to form a silicon dioxide film on the semiconductor substrate.

An object is to provide favorable interface characteristics of a thin film transistor including an oxide semiconductor layer without mixing of an impurity such as moisture. Another object is to provide a semiconductor device including a thin film transistor having excellent electric characteristics and high reliability, and a method by which a semiconductor device can be manufactured with high productivity. A main point is to perform oxygen radical treatment on a surface of a gate insulating layer. Accordingly, there is a peak of the oxygen concentration at an interface between the gate insulating layer and a semiconductor layer, and the oxygen concentration of the gate insulating layer has a concentration gradient. The oxygen concentration is increased toward the interface between the gate insulating layer and the semiconductor layer.