A method for manufacturing a shallow trench isolation structure includes: providing a substrate and forming multiple first trenches in the substrate, in which a cross-sectional width of each first trench increases downward along a vertical direction; forming a continuous first isolation layer on a top of the substrate and inner sides of the multiple first trenches by a deposition process, in which parts of the first isolation layer located in the first trenches form second trenches, and in which a cross-sectional width of each second trench remains constant downward along the vertical direction; and forming a continuous second isolation layer on a surface of the first isolation layer by an ISSG process, in which parts of the second isolation layer located in the second trenches completely fill up the second trenches.

A method of fabricating semiconductor fins, including, patterning a film stack to produce one or more sacrificial mandrels having sidewalls, exposing the sidewall on one side of the one or more sacrificial mandrels to an ion beam to make the exposed sidewall more susceptible to oxidation, oxidizing the opposite sidewalls of the one or more sacrificial mandrels to form a plurality of oxide pillars, removing the one or more sacrificial mandrels, forming spacers on opposite sides of each of the plurality of oxide pillars to produce a spacer pattern, removing the plurality of oxide pillars, and transferring the spacer pattern to the substrate to produce a plurality of fins.

A method of fabricating semiconductor fins, including, patterning a film stack to produce one or more sacrificial mandrels having sidewalls, exposing the sidewall on one side of the one or more sacrificial mandrels to an ion beam to make the exposed sidewall more susceptible to oxidation, oxidizing the opposite sidewalls of the one or more sacrificial mandrels to form a plurality of oxide pillars, removing the one or more sacrificial mandrels, forming spacers on opposite sides of each of the plurality of oxide pillars to produce a spacer pattern, removing the plurality of oxide pillars, and transferring the spacer pattern to the substrate to produce a plurality of fins.

A method for etching at least one layer of a gallium nitride (GaN)-based material is provided, the method including: providing the GaN-based layer having a front face; and at least one cycle including the following successive steps: modifying, by implanting hydrogen (H)- and/or helium (He)-based ions, at least some of a thickness of the GaN-based layer to form in the layer at least one modified portion extending from the front face, the implanting being carried out from a plasma, the modifying by implanting being carried out such that the modified portion extends from the front face and over a depth greater than 3 nm; oxidizing at least some of the modified portion by exposing the layer to an oxygen-based plasma, to define in the layer, at least one oxidized portion and at least one non-oxidized portion; and etching the oxidized portion selectively at the non-oxidized portion.

A method for etching at least one layer of a gallium nitride (GaN)-based material is provided, the method including: providing the GaN-based layer having a front face; and at least one cycle including the following successive steps: modifying, by implanting hydrogen (H)- and/or helium (He)-based ions, at least some of a thickness of the GaN-based layer to form in the layer at least one modified portion extending from the front face, the implanting being carried out from a plasma, the modifying by implanting being carried out such that the modified portion extends from the front face and over a depth greater than 3 nm; oxidizing at least some of the modified portion by exposing the layer to an oxygen-based plasma, to define in the layer, at least one oxidized portion and at least one non-oxidized portion; and etching the oxidized portion selectively at the non-oxidized portion.

In an embodiment, a device includes: a first nanostructure over a substrate, the first nanostructure including a channel region and a first lightly doped source/drain (LDD) region, the first LDD region adjacent the channel region; a first epitaxial source/drain region wrapped around four sides of the first LDD region; an interlayer dielectric (ILD) layer over the first epitaxial source/drain region; a source/drain contact extending through the ILD layer, the source/drain contact wrapped around four sides of the first epitaxial source/drain region; and a gate stack adjacent the source/drain contact and the first epitaxial source/drain region, the gate stack wrapped around four sides of the channel region.

A film-forming apparatus for forming a predetermined film on a substrate by plasma ALD includes a chamber, a stage, a shower head having an upper electrode and a shower plate insulated from the upper electrode, a first high-frequency power supply connected to the upper electrode, and a second high-frequency power supply connected to an electrode contained in the stage. A high-frequency power is supplied from the first high-frequency power supply to the upper electrode, thereby forming a high-frequency electric field between the upper electrode and the shower plate and generating a first capacitively coupled plasma. A high-frequency power is supplied from the second high-frequency power supply to the electrode, thereby forming a high-frequency electric field between the shower plate and the electrode in the stage and generating a second capacitively coupled plasma that is independent from the first capacitively coupled plasma.

A film-forming apparatus for forming a predetermined film on a substrate by plasma ALD includes a chamber, a stage, a shower head having an upper electrode and a shower plate insulated from the upper electrode, a first high-frequency power supply connected to the upper electrode, and a second high-frequency power supply connected to an electrode contained in the stage. A high-frequency power is supplied from the first high-frequency power supply to the upper electrode, thereby forming a high-frequency electric field between the upper electrode and the shower plate and generating a first capacitively coupled plasma. A high-frequency power is supplied from the second high-frequency power supply to the electrode, thereby forming a high-frequency electric field between the shower plate and the electrode in the stage and generating a second capacitively coupled plasma that is independent from the first capacitively coupled plasma.

Embodiments described herein relate to methods forming optical device structures. One embodiment of the method includes exposing a substrate to ions at an ion angle relative to a surface normal of a surface of the substrate to form an initial depth of a plurality of depths. A patterned mask is disposed over the substrate and includes two or more projections defining exposed portions of the substrate or a device layer disposed on the substrate. Each projection has a trailing edge at a bottom surface contacting the device layer, a leading edge at a top surface of each projection, and a height from the top surface to the device layer. Exposing the substrate to ions at the ion angle is repeated to form at least one subsequent depth of the plurality of depths.

Embodiments described herein relate to methods forming optical device structures. One embodiment of the method includes exposing a substrate to ions at an ion angle relative to a surface normal of a surface of the substrate to form an initial depth of a plurality of depths. A patterned mask is disposed over the substrate and includes two or more projections defining exposed portions of the substrate or a device layer disposed on the substrate. Each projection has a trailing edge at a bottom surface contacting the device layer, a leading edge at a top surface of each projection, and a height from the top surface to the device layer. Exposing the substrate to ions at the ion angle is repeated to form at least one subsequent depth of the plurality of depths.