A semiconductor substrate includes a first material layer made of a first material and including a plurality of protrusions, and a second material layer made of a second material different from the first material, filling spaces between the plurality of protrusions, and covering the plurality of protrusions. Each of the protrusions includes a tip and a plurality of facets converging at the tip, and adjacent facets of adjacent protrusions are in contact with each other,

In an embodiment, a structure includes: a contact etch stop layer (CESL) over a substrate; a fin extending through the CESL; an epitaxial source/drain region in the fin, the epitaxial source/drain region extending through the CESL; a silicide contacting upper facets of the epitaxial source/drain region; a source/drain contact contacting the silicide, lower facets of the epitaxial source/drain region, and a first surface of the CESL; and an inter-layer dielectric (ILD) layer surrounding the source/drain contact, the ILD layer contacting the first surface of the CESL.

A method includes: forming a first plurality of tiers that each comprises first and second dummy layers over a substrate, wherein within each tier, the second dummy layer is disposed above the first dummy layer; forming a second plurality of recessed regions in the first plurality of tiers, wherein at least one subgroup of the second plurality of recessed regions extend through respective different numbers of the second dummy layers; and performing an etching operation to concurrently forming a third plurality of trenches with respective different depths in the substrate through the at least one subgroup of the second plurality of recessed regions.

A method for forming reliefs on a face of a substrate is provided, successively including forming a protective screen for protecting at least a first zone of the face; an implanting to introduce at least one species comprising carbon into the substrate from the face of the substrate, the forming of the protective screen and the implanting being configured to form, in the substrate, at least one carbon modified layer having a concentration of implanted carbon greater than or equal to an etching threshold only from a second zone of the face of the substrate not protected by the protective screen; removing the protective screen; and etching the substrate from the first zone selectively with respect to the second zone.

Variations of characteristics of a semiconductor device provided with a power MOSFET having a super junction structure are suppressed, and reliability of the semiconductor device is improved. A trench embedding an insulating film, which constitutes an insulator column therein, is formed in a first main surface of a semiconductor substrate whose crystal plane is a (110) plane. A crystal plane of a side surface of the trench in a short-side direction is a (111) plane, and a p-type diffusion layer constituting a p-column is formed in the above-mentioned side surface.

A method includes etching a semiconductor substrate to form a trench, with the semiconductor substrate having a sidewall facing the trench, and depositing a first semiconductor layer extending into the trench. The first semiconductor layer includes a first bottom portion at a bottom of the trench, and a first sidewall portion on the sidewall of the semiconductor substrate. The first sidewall portion is removed to reveal the sidewall of the semiconductor substrate. The method further includes depositing a second semiconductor layer extending into the trench, with the second semiconductor layer having a second bottom portion over the first bottom portion, and a second sidewall portion contacting the sidewall of the semiconductor substrate. The second sidewall portion is removed to reveal the sidewall of the semiconductor substrate.

In a method of manufacturing a semiconductor device, a fin structure is formed by patterning a semiconductor layer, and an annealing operation is performed on the fin structure. In the patterning of the semiconductor layer, a damaged area is formed on a sidewall of the fin structure, and the annealing operation eliminates the damaged area.

According to one embodiment, an etching apparatus includes a first container including an opening covered by a semiconductor substrate; a second container including an opening covered by a catalyst layer; a first flow path configured to communicate with the first container; a second flow path configured to communicate with the second container; a cation exchange film interposed between the first flow path and the second flow path and allowing at least protons to pass through; and an electric field applier configured to apply an electric field to the semiconductor substrate.

Process flow for a stacked power diode and design of the resulting diode is disclosed. Blanket epitaxy over heavy doped wafers is performed. By controlling dopant addition during epitaxy, desired n-type, diode base, and p-type doping profiles and thicknesses achieved. V-groove pattern if formed on wafers by depositing mask film, lithography and anisotropic etch. Islands surrounded by V-grooves define individual diodes. V-grooves serve as side insulation. Next, oxidation step passivates V-grooves. Further, the mask film is stripped to open diode contact areas on both sides of wafers. Next high melting point metal and low melting point metal films are selectively electroplated on all open silicon surfaces. Stacking is performed on wafer level by bonding of desired wafer count by solid-liquid interdiffusion process. Wafer stacks are sawed into individual stacked diode dies along outer slopes of V-grooves. Final stacked devices can be used as DSRD—drift step recovery diodes. Compared to DSRDs made by known methods, better fabrication yield and higher pulse power electrical performance is achieved.

Semiconductor devices and methods of forming conductive lines in the same include forming a cut region in a first dielectric layer, the cut region having a first width. A second dielectric plug is formed in the cut region. A mask is formed, over the first dielectric layer, that defines at least one trench region that crosses the second dielectric plug, with the at least one trench region having a second width that is smaller than the first width. Material from the first dielectric layer in the trench regions is etched away, using a selective anisotropic etch that leaves the second dielectric plug in place, to form trenches in the first dielectric layer. Conductive material is deposited in the trenches to form conductive lines that are separated by the second dielectric plug.