摘要:
A layer in which the potential level difference normally unrequired for device operation is generated is positively inserted in a device structure. The potential level difference has such a function that even if a semiconductor having a small bandgap is exposed on a mesa side surface, a potential drop amount of the portion is suppressed, and a leakage current inconvenient for device operation can be reduced. This effect can be commonly obtained for a heterostructure bipolar transistor, a photodiode, an electroabsorption modulator, and so on. In the photodiode, since the leakage current is alleviated, the device size can be reduced, so that in addition to improvement of operating speed with a reduction in series resistance, it is advantageous that the device can be densely disposed in an array.
摘要:
An electron injected APD with an embedded n electrode structure in which edge breakdown can be suppressed without controlling the doping profile of an n-type region of the embedded n electrode structure with high precision. The APD comprising a buffer layer with a low ionization rate is inserted between an n electrode connecting layer and an avalanche multiplication layer. Specifically, the APD is an electron injected APD in which an n electrode layer, the n electrode connecting layer, the buffer layer, the avalanche multiplication layer, an electric field control layer, a band gap gradient layer, a low-concentration light absorbing layer, a p-type light absorbing layer, and a p electrode layer are sequentially stacked, and a light absorbing portion that includes at least the low-concentration light absorbing layer and the p-type light absorbing layer forms a mesa shape.
摘要:
A photodiode has an optical absorption layer composed of a depleted first semiconductor optical absorption layer with a layer width WD and a p-type neutral second semiconductor optical absorption layer with a layer width WA. The ratio between WA and WD is set such that the total carrier transit time τtot becomes minimum in the optical absorption layer. The photodiode can further include a depleted semiconductor optical transmission layer with a bandgap greater than that of the first semiconductor optical absorption layer, between the first semiconductor optical absorption layer and an n-type semiconductor electrode layer.
摘要:
A heterojunction bipolar transistor includes a collector contact layer constituted by a high-concentration first semiconductor layer of a first conductivity type formed on a semiconductor substrate, a collector region stacked on the collector contact layer, a base layer constituted by a fifth semiconductor layer of a second conductivity type formed on the collector region, and an emitter layer constituted by a semiconductor layer of the first conductivity type formed on the base layer. The collector region is constituted by a second semiconductor layer, a third semiconductor layer of the second conductivity type having an impurity concentration higher than that of the second semiconductor layer, and a fourth semiconductor layer of the first conductivity type having a band gap energy higher than that of each of the first and second semiconductor layers and an impurity concentration higher than that of the second semiconductor layer, and the fourth semiconductor layer and lower than that of the first semiconductor layer, the third semiconductor layer, and the second semiconductor layer are sequentially formed on the collector contact layer in an order named.
摘要:
The disclosed dulled stretched molding of at most 30% in gloss value, which is useful as a general-purpose packaging material, printing paper, tracing paper, etc., is produced from a composition comprising 100 parts by weight of a propylene-ethylene lock copolymer and 3 to 40 parts by weight of a cyclopentadiene type petroleum resin having a ring and ball softening point of at least 160.degree. C. through melt extrusion thereof and stretching of the resulting flat extrudate.There also is disclosed a heat-shrinkable foamed molding of at most 0.85 in density and at least 10% in heat shrinkability at 100.degree. C., which is useful as a packaging material, a tying material, a label material, etc. This heat-shrinkable foamed molding is produced from a composition comprising a crystalline propylene-.alpha.-olefin copolymer having a crystal melting point of at most 150.degree. C. and 5 to 40 wt. %, based on the copolymer, of a hydrogenated cyclopentadiene type resin having a ring and ball softening point of at least 160.degree. C. through melt extrusion thereof and stretching of the resulting flat extrudate.
摘要:
A heterojunction bipolar transistor includes an emitter layer of a first conductivity type, a base layer of a second conductivity type adjacent to the emitter layer, a collector buffer layer of the first conductivity type, and a collector layer arranged between the collector buffer layer and the base layer. The collector layer includes a first collector layer formed at the side of the base layer and a second collector layer arranged at the side of the collector buffer layer. The first collector layer is a semiconductor layer having an impurity concentration lower than that of the base layer. The second collector layer is a semiconductor layer of the second conductivity type having an impurity concentration higher than that of the first collector layer.
摘要:
An APD is provided with the semi-insulating substrate, a first mesa having a first laminate constitution in which a p-type electrode layer, a p-type light absorbing layer, a light absorbing layer with a low impurity concentration, a band gap inclined layer, a p-type electric field control layer, an avalanche multiplier layer, an n-type electric field control layer, and an electron transit layer with a low impurity concentration are stacked in this order on a surface of the semi-insulating substrate, a second mesa having an outer circumference provided inside an outer circumference of the first mesa as viewed from the laminating direction and having a second laminate constitution in which an n-type electrode buffer layer and an n-type electrode layer are stacked in this order on a surface on the electron transit layer side, and a depletion control region that is provided in layers on the second mesa side relative to the p-type electric field control layer, formed in an encircling portion provided inside an outer circumference of the first mesa and encircling an outer circumference of the second mesa, and prevents the encircling portion of the p-type electric field control layer from being depleted when bias is applied.
摘要:
A semiconductor optical modulator that includes a first semiconductor optical waveguide having a laminated structure including a core layer, a first clad layer, a second clad layer, and a barrier layer, the first clad layer and the second clad layer being disposed below and above the core layer, the barrier layer being inserted between the second clad layer and the core layer; a second semiconductor optical waveguide having a laminated structure in which the second clad layer has a p-type semiconductor penetrating locally through a n-type semiconductor in a laminated direction in the laminated structure of the first semiconductor optical waveguide; a first electrode connected to the first clad layer of the first semiconductor optical waveguide; and a second electrode electrically connecting the second clad layer of the first semiconductor optical waveguide and the p-type semiconductor of the second clad layer of the second semiconductor optical waveguide.
摘要:
The present invention relates to a semiconductor optoelectronic waveguide having a nin-type hetero structure which is able to stably operate an optical modulator. On the upper and lower surfaces of the core layer determined for the structure so that electro-optical effects are effectively exerted at an operating light wavelength and are provided with intermediate clad layers having a band gap which is greater than that of the core layer 11. Respectively on the upper and the lower surface of the intermediate clad layer are provided the clad layers having the band gap which is greater than those of the intermediate clad layers. On the upper surface of the clad layer are sequentially laminated a p-type layer and an n-type layer. In the applied voltage range used under an operating state, a whole region of the p-type layer and a part or a whole region of the n-type layer are depleted.
摘要:
An ultra high speed APD capable of realizing reduction in an operating voltage and quantum efficiency enhancement at the same time is provided. Under operating conditions APD, a doping concentration distribution of each light absorbing layer is determined so that a p-type light absorbing layer (16) maintains a p-type neutrality except a part thereof, and a low concentration light absorbing layer (15) is depleted. Moreover, a ratio between a layer thickness WAN of the p-type light absorbing layer (16) and a layer thickness WAD of the low concentration light absorbing layer (15) is determined so that WAD>0.3 μm and a delay time of an element response accompanying a transit of carriers generated in the light absorbing layer by light absorption takes on a local minimum under a condition that a layer thickness WA (=WAN+WAD) of the light absorbing layer is constant.
摘要翻译:提供能够同时实现工作电压降低和量子效率提高的超高速APD。 在操作条件APD下,确定每个光吸收层的掺杂浓度分布,使得p型光吸收层(16)除了其一部分之外保持p型中性,并且低浓度光吸收层(15)为 耗尽 此外,p型光吸收层(16)的层厚度W AN AN与低浓度光吸收层(15)的层厚度W SUB / SUB之比 ),使得在光吸收层中通过光吸收产生的载流子的转移伴随的元素响应的延迟时间在层的一个条件下成为局部最小值 光吸收层的厚度W A(= W AN AN + W AD AD)是恒定的。