Abstract: A memory system in which a first management unit includes an update information managing unit that manages update information indicating an updated section in status information stored in a volatile first storing unit, and an update information notifying unit that notifies a second management unit of the update information managed by the update information managing unit, and the second management unit includes a commit executing unit that collects, based on the update information, difference information of the status information from the status area when the update information is notified from the update information notifying unit, and causes a second storing unit to accumulate the difference information in a backup area.

Abstract: A semiconductor device includes a lower barrier layer 12 composed of a layer of AlxGa1-xN (0?x?1) in a state of strain relaxation, and a channel layer 13, which is composed of a layer of InyGa1-yN (0?y?1) disposed on the lower barrier layer 12, has band gap that is smaller than band gap of the lower barrier layer 12, and exhibits compressive strain. A gate electrode 1G is formed over the channel layer 13 via an insulating film 15 and a source electrode 1S and a drain electrode 1D serving as ohmic electrodes are formed over the channel layer 13. The insulating film 15 is constituted of polycrystalline or amorphous member.

Abstract: According to one embodiment, a valid-cluster search module searches valid clusters included in first blocks, in each of channels, for compaction. A read command generator generates read commands used to read, in parallel, valid clusters to be migrated to a second block. The valid clusters searched in each of the channels comprise the valid clusters to be migrated. The valid clusters to be migrated correspond to a number of clusters simultaneously written to the second block and to a second number of channels in a first number of channels. A determination module determines the second number of channels corresponding to read commands to be generated next based on a situation of issuance of the read commands.

Abstract: According to one embodiment, a data storage apparatus includes a first memory configured to store a first management table, a second memory configured to store a second management table, a counter table memory, and a controller. The first management table has address data representing a storage position of data stored in a flash memory. The second memory has address data representing valid data included in the data stored in the flash memory. The counter table memory stores a counter table showing the count value of valid data in units of addresses. The controller is configured to refer to the first management table, to compare the number of data valid in units of addresses acquired by referring to the first management table, and to perform a matching check process for determining matching between the first and second management tables from a result of the comparison.

Abstract: Provided is a semiconductor device capable of suppressing an occurrence of a punch-through phenomenon. A semiconductor device includes a substrate 1, a first n-type semiconductor layer 2, a p-type semiconductor layer 3, a second n-type semiconductor layer 4, a drain electrode 13, a source electrode 11, a gate electrode 12, and a gate insulation film 21, wherein the first n-type semiconductor layer 2, the p-type semiconductor layer 3, and the second n-type semiconductor layer 4 are laminated on the substrate 1 in this order. The drain electrode 13 is in ohmic-contact with the first n-type semiconductor layer 2. The source electrode 11 is in ohmic-contact with the second n-type semiconductor layer 4. An opening portion to be filled or a notched portion that extends from an upper surface of the second n-type semiconductor layer 4 to an upper part of the first n-type semiconductor layer 2 is formed at a part of the p-type semiconductor layer 3 and a part of the second n-type semiconductor layer 4.

Abstract: According to one embodiment, a command generator sequentially and speculatively issues channel-by-channel access commands to a memory interface in a predetermined access process. A purger returns a series of unexecuted already-issued access commands using a purge response if an error occurs in any of memory accesses via a plurality of channels. A command progress manager updates command progress information such that the command progress on each of the plurality of channels returns to a position specified in an oldest access command of a series of the returned access commands issued to the channel. The command generator issues the channel-by-channel access commands including the oldest access command to the memory interface based on the updated command progress information.

Abstract: Disclosed is an HJFET 110 which comprises: a channel layer 12 composed of InyGa1-yN (0?y?1); a carrier supply layer 13 composed of AlxGa1-xN (0?x?1), the carrier supply layer 13 being provided over the channel layer 12 and including at least one p-type layer; and a source electrode 15S, a drain electrode 15D and a gate electrode 17 which are disposed facing the channel layer 12 through the p-type layer, and provided over the carrier supply layer 13. The following relational expression is satisfied: 5.6×1011x<NA×?×t [cm?2]<5.6×1013x, where x denotes an Al compositional ratio of said carrier supply layer, t denotes a thickness of said p-type layer, NA denotes an impurity concentration, and ? denotes an activation ratio.

Abstract: Provided is a semiconductor device in which the trade-off between the withstand voltage and the on-resistance is improved and the performance is increased. A semiconductor device comprises a substrate 1, a first n-type semiconductor layer 21?, a second n-type semiconductor layer 23, a p-type semiconductor layer 24, and a third n-type semiconductor layer 25?, wherein the first n-type semiconductor layer 21?, the second n-type semiconductor layer 23, the p-type semiconductor layer 24, and the third n-type semiconductor layer 25? are laminated at the upper side of the substrate 1 in this order. The drain electrode 13 is in ohmic-contact with the first n-type semiconductor layer 21? and the source electrode 12 is in ohmic-contact with the third n-type semiconductor layer 25?.

Abstract: A memory system according to an embodiment of the present invention includes: a log overflow control unit configured, when a predetermined condition is satisfied, to prohibit a recording operation of a log and to cause a log recording unit only to perform an updating operation of a management table, and when a commit condition is satisfied after the predetermined condition has been satisfied, to prohibit a commit operation by a log reflecting unit and to cause a snapshot storing unit to perform a snapshot storing operation.

Abstract: Disclosed is an HJFET 110 which comprises: a channel layer 12 composed of InyGa1-yN (0?y?1); a carrier supply layer 13 composed of AlxGa1-xN (0?x?1), the carrier supply layer 13 being provided over the channel layer 12 and including at least one p-type layer; and a source electrode 15S, a drain electrode 15D and a gate electrode 17 which are disposed facing the channel layer 12 through the p-type layer, and provided over the carrier supply layer 13. The following relational expression is satisfied: 5.6×1011x<NA×?×t [cm?2]<5.6×1013x, where x denotes an Al compositional ratio of the carrier supply layer, t denotes a thickness of the p-type layer, NA denotes an impurity concentration, and ? denotes an activation ratio.

Abstract: According to one embodiment, a memory device includes a memory, a memory interface, a command generator, an access command returning module and a command progress manager. The memory interface accesses the memory in parallel in accordance with access commands. The command generator speculatively issues access commands to the memory interface. The access command returning module returns access commands already issued to the memory interface and unexecuted at a time of occurrence of an error, through corresponding purge responses. The command progress manager updates command progress management information such that the command progress management information indicates the oldest one of the unexecuted access commands. The command generator reissues the returned unexecuted access commands to the memory interface based on the updated command progress management information.

Abstract: According to one embodiment, a storage controller includes a condition storage, a determination module, a wear-leveling block retainer, and a data transfer controller. The condition storage is provided in a storage including a plurality of blocks, and stores block condition information including at least one of erasure time information indicating when data is erased last time and erasure count information indicating the number of times data is erased. The determination module determines whether there is a block that requires wear leveling based on the block condition information. The wear-leveling block retainer retains block identification information that identifies a block determined to require wear leveling. The data transfer controller performs compaction to transfer data stored in blocks of the storage for collecting the data in a block, and, when the block identification information is retained, transfers data stored in the block identified by the block identification information.

Abstract: A semiconductor device includes a semiconductor element having a rectangular two-dimensional geometry and serving as a heat source, a first heat sink section including the semiconductor element mounted thereon, and a second heat sink section joined to an opposite side of the first heat sink section that includes the semiconductor element. A relation among directional components of thermal conductivity is K1yy?K1xx>K1zz, where directional components of a three-dimensional thermal conductivity of the heat sink section in X, Y, and Z directions are determined as Kxx, Kyy, and Kzz. A relation among directional components of a thermal conductivity of the second heat sink section is K2zz?K2yy>K2xx or K2yy?K2zz>K2xx, where the directional components of the thermal conductivity of the second heat sink section in X, Y, and X directions are determined as K2xx, K2yy, and K2zz.

Abstract: [Problem to be Solved] Provided is a semiconductor device in which the trade-off between the pressure resistance and the on-state resistance is improved and the performance is improved.

Abstract: A field effect transistor includes a nitride-based semiconductor multi-layer structure, a source electrode (108), a drain electrode (109), a protective film (110), and a gate electrode (112) that is provided in a recess structure, which is formed by etching, directly or with a gate insulating film interposed therebetween. The nitride-based semiconductor multi-layer structure includes at least a base layer (103) made of AlXGa1-XN (0?1), a channel layer (104) made of GaN or InGaN, a first electron supply layer (105), which is an undoped or n-type AlYGa1-YN layer, a threshold value control layer (106), which is an undoped AlZGa1-ZN layer, and a second electron supply layer (107), which is an undoped or n-type AlWGa1-WN layer, epitaxially grown in this order on a substrate (101) with a buffer layer (102) interposed therebetween. The Al composition of each layer in the nitride-based semiconductor multi-layer structure satisfies 0<X?Y?1 and 0<Z?Y?1.

Abstract: A heterojunction filed effect transistor with a low access resistance, a low on resistance, and the like, a method for producing a heterojunction filed effect transistor and an electron device are provided.

Abstract: A semiconductor device, comprising: a semiconductor element 20 having a rectangular two-dimensional geometry and serving as a heat source; and a heat sink section 25 having the semiconductor element 20 mounted thereon, wherein a relation among the directional components of said thermal conductivity is: Kzz?Kyy>Kxx, where directional components of three-dimensional thermal conductivity of the heat sink section 25 in X, Y and Z directions are determined as Kxx, Kyy and Kzz, and where the longer side direction of the semiconductor element 20 is defined as X direction, the shorter side direction thereof is defined as Y direction and the thickness direction is defined as Z direction.

Abstract: A bipolar transistor is provided with an emitter layer, a base layer and a collector layer. The emitter layer is formed above a substrate and is an n-type conductive layer including a first nitride semiconductor. The base layer is formed on the emitter layer and is a p-type conductive including a second nitride semiconductor. The collector layer is formed on the base layer and includes a third nitride semiconductor. The collector layer, the base layer and the emitter layer are formed such that a crystal growth direction to the substrate surface is parallel to a substrate direction of [000-1]. The third nitride semiconductor contains InycAlxcGa1-xc-ycN (0•xc•1, 0•yc•1, 0<xc+yc•1). The a-axis length on the side of a surface in the third nitride semiconductor is shorter than the a-axis length on the side of the substrate.

Abstract: There is provided a semiconductor apparatus capable of achieving both a reverse blocking characteristic and a low on-resistance. The semiconductor apparatus includes a first semiconductor layer including a channel layer, a source electrode formed on the first semiconductor layer, a drain electrode formed at a distance from the source electrode on the first semiconductor layer, and a gate electrode formed between the source electrode and the drain electrode on the first semiconductor layer. The drain electrode includes a first drain region where reverse current between the first semiconductor layer and the first drain region is blocked, and a second drain region formed at a greater distance from the gate electrode than the first drain region, where a resistance between the first semiconductor layer and the second drain region is lower than a resistance between the first semiconductor layer and the first drain region.

Abstract: A bipolar transistor includes: a substrate; a collector and a base layer with a p-conductive-type, an emitter layer with an n-conductive-type. The collector layer is formed above the substrate and includes a first nitride semiconductor. The base layer with the p-conductive-type is formed on the collector layer and includes a second nit ride semiconductor. The emitter layer with the n-conductive-type is formed on the base layer and includes a third nitride semiconductor. The collector layer, the base layer and the emitter layer are formed so that crystal growing directions with respect to a surface of the substrate are in parallel to a [0001] direction of the substrate. The first nitride semiconductor includes: InycAlxcGa1-xc-ycN (0?xc?1, 0?yc?1, 0<xc+yc?1). In the first nitride semiconductor, a length of an a-axis on a surface side is longer than a length of an a-axis on a substrate side.