Integrated circuit structures including increased transistor source/drain (S/D) contact area using a sacrificial S/D layer are provided herein. The sacrificial layer, which includes different material from the S/D material, is deposited into the S/D trenches prior to the epitaxial growth of that S/D material, such that the sacrificial layer acts as a space-holder below the S/D material. During S/D contact processing, the sacrificial layer can be selectively etched relative to the S/D material to at least partially remove it, leaving space below the S/D material for the contact metal to fill. In some cases, the contact metal is also between portions of the S/D material. In some cases, the contact metal wraps around the epi S/D, such as when dielectric wall structures on either side of the S/D region are employed. By increasing the S/D contact area, the contact resistance is reduced, thereby improving the performance of the transistor device.

According to one embodiment, a semiconductor device includes first and second electrodes, first, second and third semiconductor regions, a first conductive portion, a gate electrode, and a second insulating portion. The first and second semiconductor regions are provided on the first semiconductor region. The third semiconductor regions are selectively provided respectively on the second semiconductor regions. The first conductive portion is provided inside the first semiconductor region with a first insulating portion interposed. The gate electrode is provided on the first conductive portion and the first insulating portion and separated from the first conductive portion. The gate electrode includes first and second electrode parts. The second insulating portion is provided between the first and second electrode parts. The second insulating portion includes first and second insulating parts. The second electrode is provided on the second and third semiconductor regions.

A semiconductor device includes a compound semiconductor layer comprising a III-V material; a first layer on the compound semiconductor layer and comprising oxygen, nitrogen, and a material included in the compound semiconductor layer; a second layer over the first layer, wherein at least a portion of the second layer comprises a single crystalline structure or a polycrystalline structure; a dielectric layer over the second layer; and a source/drain electrode extending through the dielectric layer, the second layer, and the first layer and into the compound semiconductor layer.

In a contact hole of an interlayer insulating film, a tungsten film forming a contact plug is embedded via a barrier metal. The interlayer insulating film is formed by sequentially stacked HTO and BPSG films. The BPSG film has an etching rate faster than that of the HTO film with respect to a hydrofluoric acid solution used in wet etching of preprocessing before formation of the barrier metal. After the contact hole is formed in the interlayer insulating film, a width of an upper portion of the contact hole at the BPSG film is increased in a step-like shape, to be wider than a width of a lower portion at the HTO film by the wet etching before the formation of the barrier metal, whereby an aspect ratio of the contact hole is reduced. Thus, size reductions and enhancement of the reliability may be realized.

A buffer layer formed on a substrate, a base layer formed on the buffer layer, and a channel layer formed on the base layer are provided. The base layer includes Al.sub.xGa.sub.1-xN(0<x≤1) and the composition x of Al decreases in accordance with increasing approach of the composition x to the channel layer in a thickness direction. The channel layer includes Al.sub.yGa.sub.1-yN(0<y≤1) and the composition y of Al decreases in accordance with increasing approach of the composition y to the base layer in a thickness direction.

According to an embodiment, a transistor device includes a semiconductor body. The semiconductor body has a first surface, a second surface opposing the first surface, side faces, an active area, an edge termination region that laterally surrounds the active area, a drain region of a first conductivity type at the second surface, a drift region of the first conductivity type on the drain region, and a body region of a second conductivity type that opposes the first conductivity type on the drift region. In the active area, a source region of the first conductivity type is arranged on the body region. The body region has a doping concentration that is higher in the active area than in the edge termination region.

A transistor device includes: a semiconductor body having opposing first and second surfaces; an edge termination region laterally surrounding an active area; a drain region of a first conductivity type at the second surface; and a drift region of the first conductivity type on the drain region. In the active area, a body region of a second conductivity type is on the drift region, a source region of the first conductivity type is on the body region, and at least one gate electrode is positioned in a gate trench that extends into the semiconductor body from the first surface. A superjunction structure includes columns of the second conductivity type extending into the semiconductor body substantially perpendicular to the first surface in the active area and edge termination region. A first contact extends through the body region for each second conductivity type column in the active region and is electrically conductive.

The present disclosure relates to a method for manufacturing a trench-gate MOSFET. In the method, a first trench is formed in a first region and a second trench is formed in a second region in an epitaxial layer. A first well is formed in a bottom surface of the first trench in the first region, and a body region is formed in the epitaxial layer in the second region, simultaneously in one ion implantation process with one mask being used. Thus, the method reduces a number of masks and simplifies ion implantation processes, thereby reducing manufacturing cost.

A semiconductor device includes a first MOS structure portion that includes, as its elements, a semiconductor substrate of a first conductivity type, a first semiconductor layer of the first conductivity type, a first second-semiconductor-layer of a second conductivity type, first semiconductor regions of the first conductivity type, and first gate insulating films, and a second MOS structure portion that includes, as its elements, the substrate, the first semiconductor layer, a second second-semiconductor-layer, second first-semiconductor-regions of the first conductivity type, and second gate insulating films. First and second portions include all of the elements of the first and second MOS structure portions other than the first and second first-semiconductor-regions and the first and second gate insulating films, respectively. A structure of one of the elements of the first portion is not identical to a structure of a corresponding element of the second portion.

An integrated circuit device includes a substrate including first and second fin-type active areas, a gate structure on the first and second fin-type active areas, first and second source/drain regions on the first and second fin-type active areas, respectively, a first source/drain contact on the first source/drain region and comprising first and second portions, a second source/drain contact on the second source/drain region and comprising first and second portions, the second portion having an upper surface at a lower level than an upper surface of the first portion, a first stressor layer on the upper surface of the second portion of the first source/drain contact, and a second stressor layer on the upper surface of the second portion of the second source/drain contact, the second stressor layer including a material different from a material included in the first stressor layer.