A semiconductor structure formed based on selectively recessing a middle-of-line (MOL) oxide layer of the semiconductor structure including multiple gate stacks formed on a substrate. A cap layer of the multiple gate stacks is selectively recessed. An air-gap oxide layer introducing one or more air-gaps is deposited. Chemical-mechanical planarization (CMP) is performed on the deposited air-gap oxide layer.

There is disclosed a substrate processing method for etching a substrate on which a first and a second silicon oxide layer having different film qualities are formed side by side. The substrate processing method includes: a first etching step of supplying a halogen-containing gas that is not activated to the substrate and sublimating reaction by-products generated by reaction between the halogen-containing gas and the first and the second silicon oxide layer; and a second etching step of etching the substrate by radicals generated by activating the halogen-containing gas.

A method for manufacturing a semiconductor device includes forming a structure protruding from a substrate, forming a dielectric layer covering the structure, forming a dummy layer covering the dielectric layer, and performing a planarization process to completely remove the dummy layer. A material of the dummy layer has a slower removal rate to the planarization process than a material of the dielectric layer.

The disclosure relates to methods for a multi-step plasma process to remove metal hard mask layer from an underlying hard mask layer that may be used to implement a sub-lithographic integration scheme. The sub-lithographic integration scheme may include iteratively patterning several features into the metal hard mask layer that may be transferred to the hard mask layer. However, the iterative process may leave remnants of previous films on top of the metal hard mask that may act as mini-masks that may interfere with the pattern transfer to the hard mask layer. One approach to remove the mini-masks may be to use a two-step plasma process that removes the mini-mask using a first gas mixture ratio of a carbon-containing gas and a chlorine-containing gas. The remaining metal hard mask layer may be removed using a second gas mixture ratio of the carbon-containing gas and the chlorine-containing gas.

A method for forming semiconductor devices with spacers is provided. SiCO spacers are formed on sides of features. Protective coverings are formed over first parts of the SiCO spacers, wherein second parts of the sidewalls of the SiCO spacers are not covered by the protective coverings. A conversion process is provided to the second parts of the SiCO spacers which are not covered by the protective coverings, which changes a physical property of the second parts of the SiCO spacers which are not covered by the protective coverings, wherein the protective coverings protects the first parts of the SiCO spacers from the conversion process.

A bipolar transistor is supported by a single-crystal silicon substrate including a collector contact region. A first epitaxial region forms a collector region of a first conductivity type on the collector contact region. A second epitaxial region forms a base region of a second conductivity type. Deposited semiconductor material forms an emitter region of the first conductivity type. The collector region, base region and emitter region are located within an opening formed in a stack of insulating layers that includes a sacrificial layer. The sacrificial layer is selectively removed to expose a side wall of the base region. Epitaxial growth from the exposed sidewall forms a base contact region.

Provided is a silicon carbide semiconductor device that is further reduced in resistance. Silicon carbide semiconductor device includes silicon carbide semiconductor layer disposed on a first main surface of substrate, electrode layer containing polysilicon disposed on the silicon carbide semiconductor layer with first insulating layer interposed between the electrode layer and the silicon carbide semiconductor layer, second insulating layer that covers the silicon carbide semiconductor layer and the electrode layer, first silicide electrode that is located in first opening part formed in the first insulating layer and the second insulating layer and forms ohmic contact with a part of the silicon carbide semiconductor layer, and second silicide electrode that is located in second opening part formed in the second insulating layer and is in contact with a part of the electrode layer.

The disclosed methods may include depositing an amorphous carbon layer, a SiCN layer, and a TEOS layer; planarizing the semiconductor structure; performing a non-selective etch to remove the SiCN layer, the TEOS layer, and a portion of the amorphous carbon layer; and performing a selective etch of the amorphous carbon layer. The methods may reduce step height differences between first and second regions of the semiconductor structure.

Various embodiments of improved process flows and methods are provided herein for etching high aspect ratio (HAR) features in carbon-containing hard mask layers. In the disclosed embodiments, the improved process flows and methods combine sidewall passivation and mask de-clogging steps in a single plasma process step to improve throughput when etching HAR features (such as vias, contact holes, trenches, etc.) within a carbon-containing hard mask layer. In doing so, the improved process flows and methods disclosed herein protect the sidewall surfaces of the carbon-containing hard mask layer and prevent bowing during the HAR etch process, while also reducing processing time and improving throughput.

In accordance with an embodiment, a method for producing a buried cavity structure includes providing a mono-crystalline semiconductor substrate, producing a doped volume region in the mono-crystalline semiconductor substrate, wherein the doped volume region has an increased etching rate for a first etchant by comparison with an adjoining, undoped or more lightly doped material of the monocrystalline semiconductor substrate, forming an access opening to the doped volume region, and removing the doped semiconductor material in the doped volume region using the first etchant through the access opening to obtain the buried cavity structure.