132results about How to "Improve channel mobility" patented technology

A method of fabricating a semiconductor device structure, includes: providing a substrate, providing an electrode on the substrate, forming a recess in the electrode, the recess having an opening, disposing a small grain semiconductor material within the recess, covering the opening to contain the small grain semiconductor material, within the recess, and then annealing the resultant structure.

A semiconductor device and a method of manufacturing the device using a (000-1)-faced silicon carbide substrate are provided. A SiC semiconductor device having a high voltage resistancehigh blocking voltage and high channel mobility is manufactured by opting the heat treatment method used following the gate oxidation. The method of manufacturing a semiconductor device includes the steps of forming a gate insulation layer on a semiconductor region formed of silicon carbide having a (000-1) face orientation, forming a gate electrode on the gate insulation layer, forming an electrode on the semiconductor region, cleaning the semiconductor region surface. The gate insulation layer is formed in an atmosphere containing 1% or more H₂O (water) vapor at a temperature of from 800° C. to 1150° C. to reduce the interface trap density of the interface between the gate insulation layer and the semiconductor region.

A silicon carbide semiconductor device having a MOS structure includes: a substrate; a channel area in the substrate; a first impurity area; a second impurity area; a gate insulating film on the channel area; and a gate on the gate insulating film. The channel area provides an electric current path. The channel area and the gate insulating film have an interface therebetween. The interface includes a dangling bond, which is terminated by a hydrogen atom or a hydroxyl. The interface has a hydrogen concentration equal to or larger than 2.6×10²⁰ cm⁻³.

Compression stress applying portions 20 of SiGe film are formed in the source/drain regions of the p-MOSA region 30a. Then, impurities are implanted in the p-MOS region 30a and the n-MOS region 30b to form shallow junction regions 22a, 22b and deep junction regions 23a, 23b. The impurity in the shallow junction regions 22a, 22b is prevented from being diffused immediately below the gate insulation film 15 by the thermal processing in forming the SiGe film, the short channel effect is prevented, and the hole mobility of the channel region of the p-MOS transistor 14a. The operation speed of the p-MOS transistor 13a is balanced with that of the n-MOS transistor, whereby the operation speed of the complementary semiconductor device 10 can be increased. The semiconductor device fabricating method can increase and balance the operation speed of a p-transistor with that of an n-transistor.

A semiconductor device includes a GaN-based semiconductor layer that is formed on a substrate and an opening region, an electron conduction layer formed on an inner surface of the opening region, an electron supply layer that has a larger band gap than the electron conduction layer and is formed on the electron conduction layer disposed on the inner surface of the opening region, and a gate electrode formed on a side surface of the electron supply layer in the opening region. A source electrode is formed on the GaN-based semiconductor layer. A drain electrode is connected to a surface of the GaN-based semiconductor layer opposite to the source electrode.

A SiC semiconductor device having a MOS structure includes: a SiC substrate; a channel region providing a current path; first and second impurity regions on upstream and downstream sides of the current path, respectively; and a gate on the channel region through the gate insulating film. The channel region for flowing current between the first and second impurity regions is controlled by a voltage applied to the gate. An interface between the channel region and the gate insulating film has a hydrogen concentration equal to or greater than 4.7×10²⁰ cm⁻³. The interface provides a channel surface having a (000-1)-orientation surface.

The present invention facilitates semiconductor fabrication by providing methods of fabrication that selectively apply strain to multiple regions of a semiconductor device. A semiconductor device having one or more regions is provided (102). A strain inducing liner is formed over the semiconductor device (104). A selection mechanism, such as a layer of photoresist or UV reflective coating is applied to the semiconductor device to select a region (106). The selected region is treated with a stress altering treatment that alters a type and/or magnitude of stress produced by the selected region (108).

The area of each body region is minimized, and the gate oxide films at the bottoms of the trenches are more effectively protected by depletion layers extending from the body regions.

According to the present invention, an n⁻-type drift layer and a p-type base region are stacked on an n⁺-type silicon carbide substrate, and an n⁺-type source region is formed in a predetermined region of a surface portion in the base region. A gate trench is formed in a trench groove that reaches the drift layer. A p-type body region is formed at a deeper location than the gate trench. The p-type body region is adjacent to the gate trench but is not in contact with the gate trench. When viewed from above, the gate trench having a hexagonal shape surrounds the p-type body region. The side faces of the gate trench are formed only by {11-20} planes of silicon carbide.

A semiconductor device comprises a semiconductor substrate made of silicon carbide, a gate insulating film formed on the semiconductor substrate, and a gate electrode formed on the gate insulating film. The junction surface of the semiconductor surface joined with the gate insulating film is macroscopically parallel to a nonpolar face and microscopically comprised of the nonpolar face and a polar face. In the polar face, either a Si face or a C face is dominant. A semiconductor device comprises a semiconductor substrate comprised of silicon carbide and a gate electrode formed on the semiconductor substrate. The junction surface of the semiconductor surface joined with the electrode is macroscopically parallel to a nonpolar face and microscopically comprised of the nonpolar face and a polar face. In the polar face, either a Si face or a C face is dominant. The present invention is a semiconductor device having a silicon carbide substrate, and the electrical characteristics and the stability of the interface between the electrode and the silicon carbide or between the oxide film (insulating film) and the silicon carbide in the nonpolar face of a silicon carbide epitaxial layer can be improved.

A semiconductor device is fabricated having a metal stress inducing layer that facilitates channel mobility. A gate dielectric layer is formed over a semiconductor substrate. The metal stress inducing layer is formed over the gate dielectric layer. The metal stress inducing layer has a selected conductivity type and is formed and composed to yield a select stress amount and type. A gate layer, such as a polysilicon layer, is formed over the metal stress inducing layer. The gate layer and the metal stress inducing layer are patterned to define gate structures.

The present invention facilitates semiconductor fabrication by providing methods of fabrication that selectively apply strain to channel regions of devices while mitigating masking operations employed. A CAPOLY layer is formed over an NMOS region of a semiconductor device (102). A recess etch is performed on active regions of devices within a PMOS region of the semiconductor device (104) and the CAPOLY layer prevents etching of devices within an NMOS region of the semiconductor device. Subsequently, an epitaxial formation process (106) is performed that forms or deposits epitaxial regions and introduces a first type of strain across the channel regions in the PMOS region. Then, the semiconductor device is annealed (108) to cause the CAPOLY layer to introduce a second type of strain across the channel regions in the NMOS region. After annealing, the CAPOLY layer is removed (110).

A MOSFET includes a silicon carbide substrate including a main surface having an off angle of not less than 50° and not more than 65° with respect to a {0001} plane, a buffer layer and a drift layer formed on the main surface, a gate oxide film formed on and in contact with the drift layer, and a p type body region of a p conductivity type formed in the drift layer to include a region in contact with the gate oxide film. The p type body region has a p type impurity density of not less than 5×10¹⁶ cm⁻³.

An objective of this invention is to improve an ON-state current of a field-effect transistor.

For this purpose, on a single-crystal silicon substrate 101 having a {100} plane as a principal surface are formed a gate electrode 107 extending substantially in a <010> crystal axis direction of the single-crystal silicon or an axis direction equivalent to the <010> crystal axis direction, and in both sides of the gate electrode 107, source/drain regions 129 on the surface of the single-crystal silicon substrate 101. On the surface of the single-crystal silicon substrate 101 in a region directly below the gate electrode 107 are formed a principal surface and an inclined surface 133 oblique to the principal surface along the extension direction of the gate electrode 107.

The present invention discloses a semiconductor device and a method for manufacturing the semiconductor device. The semiconductor device includes a gate insulating layer formed on an inner wall of a substrate recess, a work function material layer formed on the gate insulating layer so as to apply a tensile stress or a compressive stress to a channel of a MOS field-effect transistor, and a gate metal formed on the work function material layer. The method for manufacturing the semiconductor device includes forming a work function material layer on a gate insulating layer so as to apply a tensile stress or a compressive stress to a channel of a MOS field-effect transistor, wherein the gate insulating layer is formed on an inner wall of a substrate recess, and depositing a gate metal on the work function material layer.

A SiC semiconductor device includes: a SiC substrate having a main surface; a channel region on the substrate; first and second impurity regions on upstream and downstream sides of the channel region, respectively; a gate on the channel region through a gate insulating film. The channel region for flowing current between the first and second impurity regions is controlled by a voltage applied to the gate. An interface between the channel region and the gate insulating film has a hydrogen concentration equal to or greater than 2.6×10²⁰ cm⁻³. The interface provides a channel surface perpendicular to a (0001)-orientation plane.

The present invention facilitates semiconductor fabrication by providing methods of fabrication that selectively apply tensile strain to channel regions of devices while mitigating masking operations employed. A cap poly layer is formed over NMOS and PMOS regions of a semiconductor device. Then, a resist mask is employed to remove a portion of the cap poly layer from the PMOS region. Subsequently, the same resist mask and/or remaining portion of the cap poly layer is employed to form source/drain regions within the PMOS region by implanting a p-type dopant. Afterward, a cap poly thermal process is performed that causes tensile strain to be induced only in channel regions of devices located within the NMOS region. As a result, channel mobility and/or performance of devices located in the PMOS region is not substantially degraded.

A semiconductor device (1) includes an n-type silicon carbide substrate (2) of a high impurity concentration, an n-type silicon carbide layer (3) of a low impurity concentration disposed on the substrate, a first n-type silicon carbide region (4) of a first impurity concentration disposed on the surface of the n-type silicon carbide layer, first p-type silicon carbide regions (5) disposed as adjoined to the opposite sides of the first n-type silicon carbide region, a second n-type silicon carbide region (6) disposed selectively from the surface through the interior of the first p-type silicon carbide region, polycrystalline silicon (7) short-circuiting the first p-type silicon carbide region (5) to the second n-type silicon carbide region (6), a gate electrode (8) and a third n-type silicon carbide region (10), wherein the components thereof are individually constructed in a vertical DMOS structure. Since the polycrystalline silicon short-circuits the first p-type silicon carbide region to the second n-type silicon carbide region, the threshold voltage can be given a fixed value, and the device can be used as an actual MISFET.