摘要:
A semiconductor device includes: a first nitride semiconductor layer; a second nitride semiconductor layer formed over the first nitride semiconductor layer; and a gate electrode facing the second nitride semiconductor layer via a gate insulating film. Because the second nitride semiconductor layer is formed by stacking plural semiconductor layers with their Al composition ratios different from each other, the Al composition ratio of the second nitride semiconductor layer changes stepwise. The semiconductor layers forming the second nitride semiconductor layer are polarized in the same direction so that, among the semiconductor layers, a semiconductor layer nearer to the gate electrode has higher (or lower) intensity of polarization. In other words, the intensities of polarization of the semiconductor layers change with an inclination based on their distances from the gate electrode so that, at each interface between two semiconductor layers, the amount of negative charge becomes larger than that of positive charge.
摘要:
In a group III nitride-type field effect transistor, the present invention reduces a leak current component by conduction of residual carriers in a buffer layer, and achieves improvement in a break-down voltage, and enhances a carrier confinement effect (carrier confinement) of a channel to improve pinch-off characteristics (to suppress a short channel effect). For example, when applying the present invention to a GaN-type field effect transistor, besides GaN of a channel layer, a composition-modulated (composition-gradient) AlGaN layer in which aluminum composition reduces toward a top gradually or stepwise is used as a buffer layer (hetero buffer). To gate length Lg of a FET to be prepared, a sum a of layer thicknesses of an electron supply layer and a channel layer is selected so as to fulfill Lg/a≧5, and in such a case, the layer thickness of the channel layer is selected in a range of not exceeding 5 times (about 500 Å) as long as a de Broglie wavelength of two-dimensional electron gas accumulated in the channel layer in room temperature.
摘要:
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.
摘要:
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
摘要翻译:场效应晶体管包括氮化物基半导体多层结构,源电极(108),漏电极(109),保护膜(110)和设置在凹槽结构中的栅电极(112) ,其通过蚀刻直接形成,或者在其间插入栅极绝缘膜。 所述氮化物系半导体多层结构至少包括由Al x Ga 1-x N(0 1)构成的基极层(103),由GaN或InGaN构成的沟道层(104),第1电子供给层(105) 其是未掺杂的或n型AlYGa1-YN层,作为未掺杂的AlZGa1-ZN层的阈值控制层(106)和作为未掺杂的或n型AlWGa1的第二电子供给层(107) -WN层,在衬底(101)上依次外延生长,缓冲层(102)插入其间。 氮化物类半导体多层结构中的各层的Al组成满足0
摘要:
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
摘要翻译:公开了一种HJFET 110,其包括:由In y Ga 1-y N(0 @ y 1)组成的沟道层12; 由Al x Ga 1-x N(0 @ x 1)构成的载流子供给层13,载流子供给层13设置在沟道层12上并且包括至少一个p型层; 以及源极电极15S,漏极电极15D和栅极电极17,其通过p型层面对沟道层12,并且设置在载流子供给层13上。满足以下关系式:5.6×10×11× NA×eta×t [cm-2] <5.6×1013x,其中x表示载体供给层的Al组成比,t表示所述p型层的厚度,NA表示杂质浓度,eta表示活化 比。
摘要:
A semiconductor device capable of suppressing the occurrence of a punch-through phenomenon is provided. A first n-type conductive layer (2′) is formed on a substrate (1′). A p-type conductive layer (3′) is formed thereon. A second n-type conductive layer (4′) is formed thereon. On the under surface of the substrate (1′), there is a drain electrode (13′) connected to the first n-type conductive layer (2′). On the upper surface of the substrate (1′), there is a source electrode (11′) in ohmic contact with the second n-type conductive layer (4′), and a gate electrode (12′) in contact with the first n-type conductive layer (2′), p-type conductive layer (3′), the second n-type conductive layer (4′) through an insulation film (21′). The gate electrode (12′) and the source electrode (11′) are alternately arranged. The p-type conductive layer (3′) includes In.
摘要:
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.
摘要翻译:半导体器件包括在应变松弛的状态下由Al x Ga 1-x N(0&amp; nlE; x&nlE; 1)层构成的下阻挡层12,以及由In y Ga 1-y N(0&lt; nlE; 1)层组成的沟道层13。 y); 1)设置在下阻挡层12上,具有小于下阻挡层12的带隙的带隙,并且表现出压缩应变。 在沟道层13上经由绝缘膜15形成栅极电极1G,在沟道层13上形成有用作欧姆电极的源电极1S和漏电极1D。绝缘膜15由多晶或非晶构成。
摘要:
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. The gate electrode 12 is in contact with an upper surface of the first n-type semiconductor layer 2, side surfaces of the p-type semiconductor layer 3, and side surfaces of the second n-type semiconductor layer 4 at inner surfaces of the opening portion to be filled or a surface of the notched portion via the gate insulation film 21. The p-type semiconductor layer 3 has a positive polarization charge at a first n-type semiconductor layer 2 side in a state where a voltage is applied to none of the electrodes.
摘要:
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.
摘要:
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. In the heterojunction field effect transistor, an electron transit layer 11 formed of a III-nitride semiconductor is formed on a substrate 10, an electron supply layer 12 formed of a III-nitride semiconductor forms a heterojunction with an upper surface of the electron transit layer 11, a gate electrode 14, a source electrode 15A, and a drain electrode 15B are arranged on the electron supply layer 12, n-type conductive layer regions 13A and 13B each extended from an upper part of the electron transit layer 11 to an upper surface of the electron supply layer 12 are provided in at least a part below the source electrode 15A and a part below the drain electrode 15B, and an n-type impurity concentration at a heterojunction interface of an electron transit layer 11 part of each of the n-type conductive layer regions 13A and 13B with the electron supply layer 12 is 1×1020 cm−3 or more.