Abstract: An integrated circuit may be formed by forming a buried isolation layer in an isolation recess in a single-crystal silicon-based substrate. Exposed lateral surfaces of the substrate at the buried isolation layer are covered with a dielectric sidewall. A seed trench is formed through the buried isolation layer to expose the substrate. A single-crystal silicon-based seed layer is formed through the seed trench, extending above the top surface of the buried isolation layer. A silicon-based non-crystalline layer is formed contacting the seed layer. A cap layer is formed over the non-crystalline layer. A radiant-induced recrystallization process converts the non-crystalline layer to a single-crystal layer aligned with the seed layer. The cap layer is removed and the single-crystal layer is planarized, leaving an isolated semiconductor layer over the buried isolation layer.

Abstract: A process for assembling a first wafer and a second wafer each bevelled on their peripheries includes excavating the bevelled peripheral part of at least one first side of the first wafer to create a deposit bordering the region excavated in the material of the first wafer. The first side and a second side of the second wafer are then bonded together.

Abstract: A nanowire transistor device includes a substrate, a plurality of nanowires formed on the substrate, and a gate surrounding at least a portion of each nanowire. The nanowires respectively include a first semiconductor core and a second semiconductor core surrounding the first semiconductor core. A lattice constant of the second semiconductor core is different from a lattice constant of the first semiconductor core.

Abstract: A method for fabricating a semiconductor device is provided. The method includes forming a first fin-shaped pattern including an upper part and a lower part on a substrate, forming a second fin-shaped pattern by removing a part of the upper part of the first fin-shaped pattern, forming a dummy gate electrode intersecting with the second fin-shaped pattern on the second fin-shaped pattern, and forming a third fin-shaped pattern by removing a part of an upper part of the second fin-shaped pattern after forming the dummy gate electrode, wherein a width of the upper part of the second fin-shaped pattern is smaller than a width of the upper part of the first fin-shaped pattern and is greater than a width of an upper portion of the third fin-shaped pattern.

Abstract: A semiconductor substrate and a semiconductor device are provided. The semiconductor substrate includes a base substrate, a first silicon germanium layer on the base substrate and a second silicon germanium layer on the first silicon germanium layer. A germanium fraction of the second silicon germanium layer decreases in the direction away from the base substrate, and a germanium fraction of a lowermost part of the second silicon germanium layer is greater than a germanium fraction of an uppermost part of the first silicon germanium layer.

Abstract: A semiconductor structure includes: a germanium layer; and a first insulating film that is formed on an upper surface of the germanium layer, primarily contains germanium oxide and a substance having an oxygen potential lower than an oxygen potential of germanium oxide, and has a physical film thickness of 3 nm or less; wherein a half width of frequency to height in a 1 ?m square area of the upper surface of the germanium layer is 0.7 nm or less.

Abstract: A diamond multilayer structure comprises: a nitride semiconductor layer that have a first main surface and a second main surface and comprises a nitride semiconductor having a wurtzite structure and containing B; and a diamond layer located on the first main surface of the nitride semiconductor layer.

Abstract: A graphene compound made from the method of preparing graphene flakes or chemical vapor deposition grown graphene films on a SiO2/Si substrate; exposing the graphene flakes or the chemical vapor deposition grown graphene film to hydrogen plasma; performing hydrogenation of the graphene; wherein the hydrogenated graphene has a majority carrier type; creating a bandgap from the hydrogenation of the graphene; applying an electric field to the hydrogenated graphene; and tuning the bandgap.

Abstract: The present invention relates to a novel process for the preparation of printable, low-viscosity oxide media, and to the use thereof in the production of solar cells.

Abstract: The silicon carbide semiconductor layer includes a first impurity region, a second impurity region, and a third impurity region. Turning to a first position at which an impurity concentration 1/10 as high as a highest impurity concentration is exhibited in a concentration profile of an impurity having the first conductivity type in a direction perpendicular to the main surface in the third impurity region and a second position at which an impurity concentration 1/10 as high as a highest impurity concentration is exhibited in a concentration profile of an impurity having the second conductivity type in the direction perpendicular to the main surface in the second impurity region, a first depth from the main surface to the first position is shallower than a second depth from the main surface to the second position. The electrode is electrically connected to the second impurity region and the third impurity region.

Abstract: In a semiconductor device having a silicon carbide device, a technique capable of suppressing variation in a breakdown voltage and achieving reduction in an area of a termination structure is provided. In order to solve the above-described problem, in the present invention, in a semiconductor device having a silicon carbide device, a p-type first region and a p-type second region provided to be closer to an outer peripheral side than the first region are provided in a junction termination portion, a first concentration gradient is provided in the first region, and a second concentration gradient larger than the first concentration gradient is provided in the second region.

Abstract: A silicon carbide semiconductor device includes a silicon carbide semiconductor layer, a gate insulating film formed on the silicon carbide semiconductor layer, and a gate electrode provided on the gate insulating film, wherein the gate electrode has a polysilicon layer at least on a side of an interface with the gate insulating film, and the gate insulating film has an oxide film derived from the polysilicon layer, at an interface between the gate insulating film and the polysilicon layer of the gate electrode.

Abstract: According to one embodiment, a semiconductor device includes: a field effect transistor provided in a semiconductor layer and including a gate electrode, a source electrode, and a drain electrode; a first insulating layer provided on the field effect transistor; a first field plate electrode provided on the first insulating layer to overlap the gate electrode, and coupled to one of the gate electrode and the source electrode; a second insulating layer provided on the first field plate electrode; and a second field plate electrode provided on the second insulating layer and above the first field plate electrode, and coupled to the other one of the gate electrode and the source electrode. The second field plate electrode includes a first electrode portion and a second electrode portion spaced apart by a first space.

Abstract: A semiconductor device includes: a semiconductor substrate; and a first trench and a second trench that extend from a front surface of the semiconductor substrate toward a rear surface side of the semiconductor substrate. A gate electrode is accommodated in the first trench. An insulator is accommodated in the second trench. An angle between a bottom surface and a side surface of the first trench is larger than an angle between a bottom surface and a side surface of the second trench. A void is provided in the insulator in the second trench.

Abstract: A method of fabricating a semiconductor device includes forming fin-shaped semiconductor layers on a semiconductor substrate. First and second pillar-shaped semiconductor layers are formed, and first and second control gates are formed around the first and second pillar-shaped semiconductor layers, respectively. First and second selection gates are formed around the first and second pillar-shaped semiconductor layers, respectively. First and second contact electrodes are formed around upper portions of the first and second pillar-shaped semiconductor layers, respectively.

Abstract: A method of forming a finFET transistor device includes forming a crystalline, compressive strained silicon germanium (cSiGe) layer over a substrate; masking a first region of the cSiGe layer so as to expose a second region of the cSiGe layer; subjecting the exposed second region of the cSiGe layer to an implant process so as to amorphize a bottom portion thereof and transform the cSiGe layer in the second region to a relaxed SiGe (rSiGe) layer; performing an annealing process so as to recrystallize the rSiGe layer; epitaxially growing a tensile strained silicon layer on the rSiGe layer; and patterning fin structures in the tensile strained silicon layer and in the first region of the cSiGe layer.

Abstract: The present invention provides a semiconductor with a multilayered contact structure. The multilayered structure includes a metal contact placed on an active region of a semiconductor and a metal contact extension placed on the metal contact.

Abstract: The present invention provides a bipolar transistor, a method for forming the bipolar transistor, a method for turning on the bipolar transistor, and a band-gap reference circuit, virtual ground reference circuit and double band-gap reference circuit with the bipolar transistor. The bipolar transistor includes: a Silicon-On-Insulator wafer; a base area, an emitter area and a collector area; a base area gate dielectric layer on a top silicon layer and atop the base area; a base area control-gate on the base area gate dielectric layer; an emitter electrode connected to the emitter area via a first contact; a collector electrode connected to the collector area via a second contact; and a base area control-gate electrode connected to the base area control-gate via a third contact.

Abstract: A method of forming a memory device on a substrate having memory, LV and HV areas, including forming pairs of spaced apart memory stacks in the memory area, forming a first conductive layer over and insulated from the substrate, forming a first insulation layer on the first conductive layer and removing it from the memory and HV areas, performing a conductive material deposition to thicken the first conductive layer in the memory and HV areas, and to form a second conductive layer on the first insulation layer in the LV area, performing an etch to thin the first conductive layer in the memory and HV areas and to remove the second conductive layer in the LV area, removing the first insulation layer from the LV area, and patterning the first conductive layer to form blocks of the first conductive layer in the memory, LV and HV areas.

Abstract: A laterally diffused metal oxide semiconductor (LDMOS) transistor structure with improved unclamped inductive switching immunity. The LDMOS includes a substrate and an adjacent epitaxial layer both of a first conductivity type. A gate structure is above the epitaxial layer. A drain region and a source region, both of a second conductivity type, are within the epitaxial layer. A channel is formed between the source and drain region and arranged below the gate structure. A body structure of the first conductivity type is at least partially formed under the gate structure and extends laterally under the source region, wherein the epitaxial layer is less doped than the body structure. A conductive trench-like feed-through element passes through the epitaxial layer and contacts the substrate and the source region. The LDMOS includes a tub region of the first conductivity type formed under the source region, and adjacent laterally to and in contact with said body structure and said trench-like feed-through element.

Abstract: There are provided a method of manufacturing a thin film transistor and a display including a thin film transistor. The method of manufacturing a thin film transistor includes forming a barrier layer cm a substrate, forming a semiconductor layer on the barrier layer, forming a gate insulating layer on the semiconductor layer, forming a gate electrode on the gate insulating layer, forming an offset region on an external surface of the gate electrode through a plasma heat treatment process or an annealing process, etching, an offset region of the gate electrode, etching a gate insulating layer except for a portion of the gate insulating layer, positioned below the gate electrode, forming an interlayer insulating layer on the gate electrode, and etching, the interlayer insulating layer to form a source electrode and a drain electrode.

Abstract: After formation of a gate structure and a gate spacer, portions of an insulator layer underlying a semiconductor fin are etched to physically expose semiconductor surfaces of an underlying semiconductor material layer from underneath a source region and a drain region. Each of the extended source region and the extended drain region includes an anchored single crystalline semiconductor material portion that is in epitaxial alignment to the single crystalline semiconductor structure of the underlying semiconductor material layer and laterally applying a stress to the semiconductor fin. Because each anchored single crystalline semiconductor material portion is in epitaxial alignment with the underlying semiconductor material layer, the channel of the fin field effect transistor is effectively stressed along the lengthwise direction of the semiconductor fin.

Abstract: A method for manufacturing a semiconductor device includes forming a fin structure having a top surface and side surfaces. A mask layer is disposed over the top surface. A doping support layer is formed to cover part of the fin structure. A first impurity is introduced into a first region of the fin structure covered by the doping support layer, by implanting the first impurity into the doping support layer so that the implanted first impurity is introduced into the first region of the fin structure through the side surfaces.

Abstract: A bipolar junction transistor comprises a semiconductor layer disposed on an insulating material, at least a portion of the semiconductor layer forming a base region. The bipolar junction transistor further comprises a transistor emitter laterally disposed on a first side of the base region, where in the transistor emitter is a first doping type and has a first width, and wherein the first width is a lithographic feature size. The bipolar junction transistor further comprises a transistor collector laterally disposed on a second side of the base region, wherein the transistor collector is the first doping type and the first width. The bipolar junction transistor further comprises a central base contact laterally disposed on the base region between the transistor emitter and the transistor collector, wherein the central base contact is a second doping type and has a second width, and wherein the second width is a sub-lithographic feature size.

Abstract: A compound semiconductor device includes: a substrate; a first barrier layer of a nitride semiconductor formed over the substrate; a well layer of a nitride semiconductor formed over the first barrier layer; and a second barrier layer of a nitride semiconductor formed over the well layer, wherein the first barrier layer, the well layer, and the second barrier layer each include a first region having, as an upper surface, a (0001) plane in terms of crystal orientation and a second region having, as an upper surface, a (000-1) plane in terms of crystal orientation, the first region of the first barrier layer, the first region of the well layer, and the first region of the second barrier layer are stacked, the second region of the first barrier layer, the second region of the well layer, and the second region of the second barrier layer are stacked.

Abstract: A method of fabricating a multi-layer epitaxial buffer layer stack for transistors includes depositing a buffer stack on a substrate. A first voided Group IIIA-N layer is deposited on the substrate, and a first essentially void-free Group IIIA-N layer is then deposited on the first voided Group IIIA-N layer. A first high roughness Group IIIA-N layer is deposited on the first essentially void-free Group IIIA-N layer, and a first essentially smooth Group IIIA-N layer is deposited on the first high roughness Group IIIA-N layer. At least one Group IIIA-N surface layer is then deposited on the first essentially smooth Group IIIA-N layer.

Abstract: A semiconductor device comprises a Group III nitride semiconductor lamination structure including a hetero-junction; an insulating layer formed on the Group III nitride semiconductor lamination structure, the insulating layer including a gate opening portion extending to the Group III nitride semiconductor lamination structure; a gate insulating film configured to cover a bottom portion and a side portion of the gate opening portion; a gate electrode formed on the gate insulating film in the gate opening portion; a source electrode and a drain electrode disposed in a spaced-apart relationship with the gate electrode to sandwich the gate electrode and electrically connected to the Group III nitride semiconductor lamination structure; and a conductive layer embedded in the insulating layer between the gate electrode and the drain electrode and insulated from the gate electrode by the gate insulating film, the conductive layer electrically connected to the source electrode.

Abstract: An enhancement mode high electron mobility transistor according to an embodiment of the present invention includes: a substrate; a channel layer, prepared above the substrate; a barrier layer, prepared above the channel layer; the barrier layer and the channel layer forming a heterojunction structure, and two dimensional electron gas being formed at an interface between the barrier layer and the channel layer; a groove, prepared inside the barrier layer; a semiconductor epitaxial layer, prepared above the groove by secondary growth; an in-situ dielectric layer, prepared above the semiconductor epitaxial layer; a gate electrode, prepared above the in-situ dielectric layer; a source electrode, prepared above the barrier layer; and a drain electrode, prepared above the barrier layer.

Abstract: A radio frequency (RF) power transistor includes a semiconductor heterostructure, a gate electrode, a drain electrode and a source electrode. The drain electrode includes an ohmic contact and a Schottky contact extending from the ohmic contact toward the gate electrode, spaced apart from the gate electrode (4) by a distance (LGD), and having a length (LEXT) being not less than 2 ?m and not greater than 4 ?m. A ratio of the length (LEXT) to a sum of the length (LEXT) and a distance (LGD) is greater than 0.83 and less than 0.98.

Abstract: Embodiments of the invention include a method for fabricating a semiconductor device and the resulting structure. The method can include providing a substrate. The method can include forming a fin on the substrate. The method can include forming a dummy gate on the fin and the substrate. The method can include etching portions of the fin not located below the dummy gate. The method can include epitaxially forming doped source and drain regions on the exposed sides of the fin. The method can include forming an insulative spacer on exposed sides of the dummy gate. The method can include forming one or more metal regions adjacent to the doped source and drain regions.

Abstract: A thin film transistor (TFT) and a display device including the same capable of displaying an image having a uniform luminance are provided, the TFT including a gate electrode; a gate insulating layer disposed on the gate electrode; a semiconductor layer disposed on the gate insulating layer; a source electrode and a drain electrode disposed on the semiconductor layer while being spaced apart from one another; and a protective layer disposed on the source electrode and the drain electrode and having a contact hole through which a portion of the drain electrode is exposed, wherein the drain electrode includes a first drain electrode overlapping a portion of the gate electrode, a second drain electrode extending from the first drain electrode and having a portion exposed through the contact hole, and a third drain electrode branched from the first drain electrode to be spaced apart from the second drain electrode.

Abstract: A method for producing a substrate for a metal-oxide-semiconductor field-effect transistor or a micro-electromechanical system includes dry etching a preliminary trench into the substrate by using a structured first masking layer. The substrate includes a silicon carbide layer, and the dry etching is carried out in such a way that a remnant of the first structured masking layer remains. The method further includes applying a second masking layer at least to walls of the preliminary trench and dry etching by using the remnant of the first masking layer and the second masking layer so as to produce a trench with a step in the trench.

Abstract: A semiconductor device includes a first load contact, a second load contact and a semiconductor region positioned between the first and second load contacts. The semiconductor region includes: a first semiconductor contact zone in contact with the first load contact; a second semiconductor contact zone in contact with the second load contact; a first conductivity type semiconductor drift zone between the first and second semiconductor contact zones, wherein the semiconductor drift zone couples the first semiconductor contact zone to the second semiconductor contact zone. The semiconductor device further comprises: a trench comprising a control electrode and an insulator. The control electrode extends for at least 75% of the semiconductor drift zone. A drift zone doping concentration and an extension of the semiconductor drift zone defines a blocking voltage of the semiconductor device. The insulator is configured for insulating a voltage that amounts to at least 50% of said blocking voltage.

Abstract: A semiconductor device includes an active region, a gate conductor and a source electrode. The active region includes a drain region, a channel region stacked on the drain region, and a source region stacked on the channel region. The active region is formed of a silicon semiconductor layer. The gate conductor is embedded within a trench, which is formed from the source region to the drain region penetrating through the channel region. The source electrode is formed to come in contact with the source region and includes an adhesion layer. The source electrode is formed of a metal layer having a film thickness of 150 ? or smaller. The interface between the source electrode and the source region is silicidized.

Abstract: In a particular embodiment, an apparatus includes an electron tunnel structure. The electron tunnel structure includes a tunneling layer, a channel layer, a source layer, and a drain layer. The tunneling layer and the channel layer are positioned between the source layer and the drain layer. The transistor device further includes a high-k dielectric layer adjacent to the electron tunnel structure.

Abstract: A field effect transistor arrangement having as planar channel layer comprises semiconductor material, the whole surface of the underside of the layer being applied to an upper side of an electrically insulating substrate layer and the upper side of the planar channel layer being covered by an insulation layer. The arrangement has a source electrode on a first side edge of the channel layer and a drain electrode on a second side edge of the channel layer and a control electrode arranged above the channel layer. An adjusting electrode is arranged on an underside of the substrate layer. A contact region between the source and drain electrodes and the planar channel layer is in each case configured as a midgap Schottky barrier. A respective barrier control electrode is arranged in the vicinity of the contact region of the source electrode and of the drain electrode, Each barrier control electrode can have a section that projects outwards in the direction of the planar channel layer.

Abstract: A semiconductor device including a channel region formed in a semiconductor substrate; a source region formed on one side of the channel region; a drain region formed on the other side of the channel region; a gate electrode formed on the channel region with a gate insulating film therebetween; and a stress-introducing layer that applies stress to the channel region, the semiconductor device having a stress distribution in which source region-side and drain region-side peaks are positioned between a pn junction boundary of the channel region and the source region and a pn junction boundary of the channel region and the drain region.

Abstract: A method of fabricating one or more semiconductor devices includes forming a trench in a semiconductor substrate, performing a cycling process to remove contaminants from the trench, and forming an epitaxial layer on the trench. The cycling process includes sequentially supplying a first reaction gas containing germane, hydrogen chloride and hydrogen and a second reaction gas containing hydrogen chloride and hydrogen onto the semiconductor substrate.

Abstract: A method of forming a finFET transistor device includes forming a crystalline, compressive strained silicon germanium (cSiGe) layer over a substrate; masking a first region of the cSiGe layer so as to expose a second region of the cSiGe layer; subjecting the exposed second region of the cSiGe layer to an implant process so as to amorphize a bottom portion thereof and transform the cSiGe layer in the second region to a relaxed SiGe (rSiGe) layer; performing an annealing process so as to recrystallize the rSiGe layer; epitaxially growing a tensile strained silicon layer on the rSiGe layer; and patterning fin structures in the tensile strained silicon layer and in the first region of the cSiGe layer.

Abstract: A method includes performing a first epitaxy to grow a silicon germanium layer over a semiconductor substrate, performing a second epitaxy to grow a silicon layer over the silicon germanium layer, and performing a first oxidation to oxidize the silicon germanium layer, wherein first silicon germanium oxide regions are generated. A strain releasing operation is performed to release a strain caused by the first silicon germanium oxide regions. A gate dielectric is formed on a top surface and a sidewall of the silicon layer. A gate electrode is formed over the gate dielectric.

Abstract: A semiconductor device includes a fin structure protruding from a substrate and having a top face and a first side face and a second side face opposite to the first side face, and first semiconductor layers disposed over the first and second side faces of the fin structure. A thickness in a vertical direction of the first semiconductor layers is smaller than a height of the fin structure.

Abstract: Semiconductor devices and methods for manufacturing the same are provided. An example semiconductor device may include: a Semiconductor on Insulator (SOI) substrate, including a base substrate, a buried dielectric layer and an SOI layer, an active area disposed on the SOI substrate and including a first sub-area and a second sub-area, wherein the first sub-area includes a first fin portion, the second sub-area includes a second fin portion opposite to the first fin portion, and at least one of the first sub-area and the second sub-area includes a laterally extending portion; a back gate arranged between the first fin portion and the second fin portion; back gate dielectric layers sandwiched between the back gate and the respective fin portions; and a gate stack formed on the active area.

Abstract: A semiconductor device includes a first oxide insulating layer over a first insulating layer, an oxide semiconductor layer over the first oxide insulating layer, a source electrode layer and a drain electrode layer over the oxide semiconductor layer, a second insulating layer over the source electrode layer and the drain electrode layer, a second oxide insulating layer over the oxide semiconductor layer, a gate insulating layer over the second oxide insulating layer, a gate electrode layer over the gate insulating layer, and a third insulating layer over the second insulating layer, the second oxide insulating layer, the gate insulating layer, and the gate electrode layer. A side surface portion of the second insulating layer is in contact with the second oxide insulating layer. The gate electrode layer includes a first region and a second region. The first region has a width larger than that of the second region.

Abstract: The present invention provides a TFT on a polymer substrate and a method for producing the TFT. The TFT is, due to its characteristics, particularly suited for applications as backplane in LCD displays and solar cell devices.

Abstract: Provided is a bottom-gate transistor including an oxide semiconductor, in which electric-field concentration which might occur in the vicinity of an end portion of a drain electrode layer (and the vicinity of an end portion of a source electrode layer) when a high gate voltage is applied to a gate electrode layer is reduced and degradation of switching characteristics is suppressed, so that the reliability is improved. The cross-sectional shape of an insulating layer which overlaps over a channel formation region is a tapered shape. The thickness of the insulating layer which overlaps over the channel formation region is 0.3 ?m or less, preferably 5 nm or more and 0.1 ?m or less. The taper angle ? of a lower end portion of the cross-sectional shape of the insulating layer which overlaps over the channel formation region is 60° or smaller, preferably 45° or smaller, further preferably 30° or smaller.

Abstract: A flash memory device in a dual fin single floating gate configuration is provided. Semiconductor fins are formed on a stack of a back gate conductor layer and a back gate dielectric layer. Pairs of semiconductor fins are formed in an array environment such that shallow trench isolation structures can be formed along the lengthwise direction of the semiconductor fins within the array. After formation of tunneling dielectrics on the sidewalls of the semiconductor fins, a floating gate electrode is formed between each pair of proximally located semiconductor fins by deposition of a conformal conductive material layer and an isotropic etch. A control gate dielectric and a control gate electrode are formed by deposition and patterning of a dielectric layer and a conductive material layer.

Abstract: This disclosure provides p-type metal oxide semiconductor thin films that display good thin film transistor (TFT) characteristics. The p-type metal oxide thin films include ternary or higher order tin-based (Sn-based) p-type oxides such as Sn (II)-M-O oxides where M is a metal. In some implementations, M is a metal selected from the d block or the p block of the periodic table. The oxides disclosed herein exhibit p-type conduction and wide bandgaps. Also provided are TFTs including channels that include p-type oxide semiconductors, and methods of fabrication. In some implementations, the p-channel TFTs have low off-currents.

Abstract: A semiconductor device according to an embodiment includes a first region including an oxide semiconductor containing indium (In), gallium (Ga), and zinc (Zn), a second region and a third region between which the first region is disposed, at least one of the second region and the third region having a higher indium (In) concentration than the first region and containing at least one metal element from the group consisting of titanium (Ti), tungsten (W), copper (Cu), zinc (Zn), aluminum (Al), lead (Pb), and tin (Sn), an electrode; and an insulating layer disposed between the first region and the electrode.

Abstract: A miniaturized transistor is provided. A transistor with low parasitic capacitance is provided. A transistor with high frequency characteristics is provided. A semiconductor device including the transistor is provided. A miniaturized semiconductor device includes an oxide semiconductor, the first conductor, the second conductor, the third conductor, the first insulator, and the second insulator. The first conductor is embedded in a region between the second conductor and the third conductor with the first insulator positioned between the first conductor and the region.

Abstract: It is an object to provide a highly reliable semiconductor device with good electrical characteristics and a display device including the semiconductor device as a switching element. In a transistor including an oxide semiconductor layer, a needle crystal group provided on at least one surface side of the oxide semiconductor layer grows in a c-axis direction perpendicular to the surface and includes an a-b plane parallel to the surface, and a portion except for the needle crystal group is an amorphous region or a region in which amorphousness and microcrystals are mixed. Accordingly, a highly reliable semiconductor device with good electrical characteristics can be formed.