Fujitsu Corporation

Toshikazu Inoue

Takashi Eshita

Kanetake Takasaki

Michio Kusayanagi

Akio Morimoto

Nobuo Iguchi

Kazuya Kumazaki

Mineharu Hattori

Shinya Nakagaki

Tetsuji Ichikawa

A converter for connecting its ATM network with other ATM networks through a LAN, which is provided with an address translation table storing external VPIs, internal VPIs uniquely assigned to the LAN, and opposing MAC addresses for opposing converters in correspondence and a processing unit for performing control for transmitting, to the LAN, frames changed from the external VPI/VCIs of headers of cells from its ATM network to the internal VPI/VCIs by referring to the address translation table and having opposing MAC addresses corresponding to the internal VPI/VCIs attached, removing the opposing MAC addresses of frames received from the LAN by referring to the address translation table, and transmitting cells changed from internal VPI/VCIs to external VPI/VCIs to its ATM network.

Converter and communication control method

A monocrystalline layer of a III-V type or II-VI type compound semiconductor is epitaxially grown on a silicon substrate, and then subjected to a plurality of reheating steps during the cooling stage, wherein at least one of the upper limit temperatures of the reheating steps is lower than that used in the growing stage. The etch pit density is reduced to less than 10.sup.6 cm.sup.-2.

Process for growing semiconductor layer on substrate

A semiconductor device comprises a substrate of a first material, a buffer layer of a second, group III-V semiconductor material provided on the substrate epitaxially, and a barrier layer of a third, group III-V compound semiconductor material different from the first and second materials and having a resistivity substantially larger than the resistivity of the buffer layer. The barrier layer further has a second lattice constant different from the lattice constant of the buffer layer and characterized by a band gap substantially larger than the band gap of the buffer layer. The barrier layer is provided on the buffer layer directly and an active layer of a fourth, group III-V compound semiconductor layer is provided on the barrier layer. On the active layer, an active device is provided such that the active device at least has a part formed in the active layer.

Semiconductor device having a group III-V epitaxial semiconductor layer

A semiconductor service having a group III-V compound semiconductor layer formed on a buffer structure for intercepting propagation of defects, in which the buffer structure comprises a first material layer of a group III-V compound semiconductor material, a second material layer of a group III-V compound semiconductor material provided on the first material layer, the second material layer containing a first group III element and a second group III element different from the first group III element with a graded compositional profile in which the content of the second group III element is decreased towards an upper boundary and a lower boundary of the second material layer.

Semiconductor device having a buffer structure for eliminating defects

A semiconductor device comprises a substrate, a compound semiconductor layer provided on the substrate, and an active region formed on the compound semiconductor layer. The substrate in turn comprises a first semiconductor layer of a first semiconductor material, a second semiconductor layer of a second semiconductor material and provided on the first semiconductor layer, and a third semiconductor layer provided on the second semiconductor layer. The third semiconductor layer has a plurality of segments each defined by a pair of side walls that extend substantially perpendicular to the third semiconductor layer. The plurality of segments have a plurality of first-type segments and a plurality of second-type segments wherein the first- and second-type segments are arranged alternately when viewed in a direction parallel to the third semiconductor layer. The first- and second-type segments have respective lattice constants that differ with each other such that a stress field acting substantially perpendicular to the third semiconductor layer is induced in the third semiconductor layer.

Semiconductor device having a heteroepitaxial substrate

A semiconductor device comprises a first semiconductor layer made of a single crystal of a first semiconductor material having a first lattice constant, a second semiconductor layer comprising a single crystal of a second semiconductor material having a second lattice constant which is different from the first lattice constant, a third semiconductor layer made of a third semiconductor material having a third lattice constant which is different from the first lattice constant, the third semiconductor layer being grown heteroepitaxially on the first semiconductor layer, a fourth semiconductor layer made of a fourth semiconductor material having a fourth lattice constant which is different from the third lattice constant, the fourth semiconductor layer being grown heteroepitaxially on the third semiconductor layer in a manner such that the second semiconductor layer is provided thereon, for preventing a first group of dislocations created in the third semiconductor layer from reaching the second semiconductor layer after passing through the fourth semiconductor layer, the fourth semiconductor layer having a thickness chosen to be larger than a critical thickness above which thickness a second group of dislocations are created in the fourth semiconductor layer, the thickness of the fourth semiconductor layer being further optimized to an optimum thickness above which thickness and below which thickness there is caused an increase of the dislocation density in the second semiconductor layer, and an active semiconductor device provided on the second semiconductor layer.

Growing community of inventors

Yokohama, Japan

Toshikazu Inoue