Provided is a plasma etching method which enables etching with high accuracy while controlling and reducing surface roughness of a transition metal film. The etching is performed for the transition metal film, which is formed on a sample and contains a transition metal element, by a first step of isotropically generating a layer of transition metal oxide on a surface of the transition metal film while a temperature of the sample is maintained at 100° C. or lower, a second step of raising the temperature of the sample to a predetermined temperature of 150° C. or higher and 250° C. or lower while a complexation gas is supplied to the layer of transition metal oxide, a third step of subliming and removing a reactant generated by an reaction between the complexation gas and the transition metal oxide formed in the first step while the temperature of the sample is maintained at 150° C. or higher and 250° C. or lower, and a fourth step of cooling the sample.

A semiconductor structure and a method for forming the semiconductor structure are provided. The method includes: providing a substrate; forming a dummy gate structure including a dummy gate dielectric layer, an initial dummy gate electrode layer, and a first sidewall spacer; forming an isolation layer having a surface lower than or coplanar with the dummy gate structure; forming a dummy gate electrode layer having a surface lower than the isolation layer, and forming a first opening to expose a portion of the first sidewall spacer; forming a modified sidewall spacer from the exposed first sidewall spacer; forming a second opening by removing the dummy gate electrode layer; forming a third opening by removing the dummy gate dielectric layer and the modified sidewall spacer, where top of the third opening has a size larger than bottom of the third opening; and forming a gate structure in the third opening.

An integrated circuit device according to the inventive concepts includes lower wiring structures formed on a substrate, an air gap arranged between the lower wiring structures, a capping layer covering an upper surface of the air gap, an etch stop layer conformally covering an upper surfaces of the lower wiring structures and the capping layer and having a protrusion and recess structure, an insulating layer covering the etch stop layer, and an upper wiring structure penetrating the insulating layer and connected to the upper surface of the lower wiring structure not covered with the etch stop layer, wherein the upper wiring structure covers a portion of an upper surface of the capping layer, and a level of the upper surface of the capping layer is higher than a level of the upper surface of the lower wiring structures.

In an embodiment, a method includes: forming a fin extending from a substrate; forming a first gate mask over the fin, the first gate mask having a first width; forming a second gate mask over the fin, the second gate mask having a second width, the second width being greater than the first width; depositing a first filling layer over the first gate mask and the second gate mask; depositing a second filling layer over the first filling layer; planarizing the second filling layer with a chemical mechanical polish (CMP) process, the CMP process being performed until the first filling layer is exposed; and planarizing the first filling layer and remaining portions of the second filling layer with an etch-back process, the etch-back process etching materials of the first filling layer, the second filling layer, the first gate mask, and the second gate mask at the same rate.

A process includes (a) providing a semiconductor substrate having a planar surface; (b) forming a plurality of thin-film layers above the planar surface of the semiconductor substrate, one on top of another, including among the thin-film layers first and second isolation layers, wherein a significantly greater concentration of a first dopant specie is provided in the first isolation layer than in the second isolation layer; (c) etching along a direction substantially orthogonal to the planar surface through the thin-films to create a trench having sidewalls that expose the thin-film layers; (d) depositing conformally a semiconductor material on the sidewalls of the trench; (e) annealing the first isolation layer at a predetermined temperature and a predetermined duration such that the first isolation layer act as a source of the first dopant specie which dopes a portion of the semiconductor material adjacent the first isolation layer; and (f) selectively etching the semiconductor material to remove the doped portion of the semiconductor material without removing the remainder of the semiconductor material.

Methods and systems for selective deposition of conductive a cap for FAV features are described. In an embodiment, a method may include receiving a substrate having an interlayer dielectrics (ILD) layer, the ILD layer having a recess, the recess having a conductive layer formed therein, the conductive layer comprising a first conductive material. Additionally, such a method may include forming a cap within a region defined by the recess and in contact with a surface of the conductive layer, the cap comprising a second conductive material. The method may also include forming a conformal etch stop layer in contact with a surface of the cap and in contact with a region of the ILD layer. Further, the method may include selectively etching the etch stop layer using a plasma etch process, wherein the plasma etch process removes the etch stop layer selective to the second conductive material comprising the cap.

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.

The embodiments of the present disclosure provide an etching method, an air-gap dielectric layer, and a dynamic random-access memory. The etching method is configured to selectively etch a silicon oxide film on a wafer surface that includes the silicon oxide film and a silicon nitride film. In addition, the etching method includes: a surface layer removal process including: etching the silicon oxide film at a first etching rate and removing a surface modification layer covering on the silicon nitride film; and an etching process including: etching the silicon oxide film at a second etching rate. The first etching rate is smaller than the second etching rate. In the etching method according to the present disclosure, through selectively etching the silicon oxide film, a substantial degradation of an etching selectivity ratio of SiO.sub.2/SiN caused by the surface modification layer on the wafer surface can be avoided. Through making the first etching rate smaller than the second etching rate, a highly efficient etching process is ensured and at the same time, excessive etching can be avoided in the surface layer removal process, thereby further ensuring the high etching selectivity ratio.

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.

Provided is an etching method that can ameliorate defects caused by etching during processing contact holes in a semiconductor device. The etching method includes attracting and adhering a first polymerization film onto an insulating film disposed on a semiconductor layer that contains silicon by plasma of a first gas, removing the first polymerization film by plasma of a second gas, and simultaneously, oxidizing an upper surface of the insulating film to form an alteration layer, attracting and adhering a second polymerization film onto the alteration layer by plasma of a third gas, and removing the second polymerization film and the alteration layer by plasma of a fourth gas.