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Oomori H.,Power Device Development Division | Matsui T.,Transmission Devices Laboratory | Tanaka Y.,Transmission Devices Laboratory | Tanaka H.,Transmission Devices Laboratory | Tsumura E.,Transmission Devices Laboratory
SEI Technical Review

One of the keys to enhancing optical networking capacity is increasing the number of optical transceivers on a network card. A new compact optical transceiver called "CFP4" has been developed for 100 Gbit/s systems. Because of a compact integrated optical transmitter and receiver, the size of the transceiver is less than 1/6th in comparison with the conventional 100 Gbit/s CFP transceiver. Its power consumption is less than 5.3 W at any operating case temperature by leveraging the multi-channel shuntdriving technique. The small size and low power consumption contribute to the expansion of the transmission capacity of the network card. The transceiver complies with IEEE (Institute of Electrical and Electronic Engineers) standards and CFP MSA (Centum gigabit Form factor Pluggable Multi-Source Agreement) specifications. The CFP4 transceiver supports the same management interface as the CFP transceiver, thus making it possible to reuse existing firmware. Additionally, the CFP4 transceiver newly implements in-service firmware upgrading. This paper describes the superior optical and electrical properties of the transceiver as well as some of the design features. Source

Toyoshima S.,Power Device Development Division | Hatsukawa S.,Power Device Development Division | Hirakata N.,Energy System Division | Tsuno T.,Power Device Development Division | Mikamura Y.,Power Device Development Division
SEI Technical Review

A silicon carbide (SiC) power module can offer a higher speed switching performance compared to a silicon (Si) power module. The excessive voltage overshooting caused by the fast turn off switching may damage the power module or the application system itself by exceeding its absolute maximum ratings, where the voltage overshooting must be proportional to the current changing rate and the stray inductance in the module. In order to avoid such large overshooting, the reduction of the inductance is necessary. To overcome such problems, we optimized the inductance with a commercially available 3-dimensional electro-magnetic field simulator, and we assembled a SiC MOSFET with the low on-resistance in the module. As a result, we have successfully developed a module suitable for high speed switching in 20 ns. © 2015, Sumitomo Electric Industries Ltd. All rights reserved. Source

Kitabayashi H.,Power Device Development Division | Ishihara K.,Compound Semiconductor Materials Division | Kawabata Y.,Power Device Development Division | Matsubara H.,Compound Semiconductor Materials Division | And 3 more authors.
SEI Technical Review

We have developed super high brightness infrared light emitting diodes (LEDs). The LEDs at the wavelength of 870 nm reached record-breaking output power of 9.8 mW, which was more than 1.3 times higher than the evaluated value of the conventional 850 nm LEDs. These super high brightness infrared LEDs can be fabricated without using time- and cost-consuming wafer bonding technologies such as metal bonding and glue bonding. They are also free from reliability issues possibly arising from the bonding interfaces. The new super high brightness infrared LEDs are promising as a light source for future applications such as high sensitivity sensors. Source

Hiyoshi T.,Power Device Development Division | Masuda T.,Power Device Development Division | Wada K.,Power Device Development Division | Harada S.,Power Device Development Division | And 2 more authors.
SEI Technical Review

SiC metal oxide semiconductor (MOS) devices are promising candidates for high power, high speed, and high temperature switches owing to their superior properties such as wide bandgap, high breakdown electric field, high saturation velocity and high thermal conductivity. However, the excellent device characteristics expected from these physical properties have not been realized, due to the issues related to SiO2/SiC interface. Although several methods to improve the interface state have been reported, the issues of SiO2/SiC interface have not been solved. In this paper, the authors improved the interface properties by using a 4H-SiC(0-33-8) face. The fabricated MOS field effect transistor (MOSFET) showed high channel mobility compared to the conventional crystal face (4H-SiC(0001)). In addition, the MOSFET showed a low on-resistance of 4 m cm2 with a blocking voltage of 890 V. Source

Saitoh Y.,Power Device Development Division | Hiyoshi T.,Power Device Development Division | Wada K.,Power Device Development Division | Masuda T.,Japan Advanced Institute of Industrial Technology | And 2 more authors.
SEI Technical Review

We have been developing a metal-oxide-semiconductor field effect transistor (MOSFET) that has a V-groove shaped trench structure. Forming a 4H-SiC {0338} facet by thermochemical etching followed by thermal oxidation on the channel region of a trench MOSFET, we obtained low on-resistance because of excellent MOS interface characteristics. Furthermore, we introduced an electric field concentration layer with a p+ type buried region into a drift layer in order to raise high breakdown voltage, suppressing gate insulation film breakdown in the trench bottom. Specific on-resistance and breakdown voltage of the trench MOSFET were measured to be 3.5 mΩcm2 (VGS = 18 V, VDS = 1 V) and 1,700 V, respectively. The introduction of the optimized p+ type buried region improved the breakdown voltage of the trench MOSFETs, and no performance degradation in the specific on-resistance and in the switching capability was confirmed. The typical turn-on and turn-off switching time for the resistive load switching characteristic were estimated to be 92 ns and 27 ns, respectively, at a drain voltage of 600 V. We also tested the stability of threshold voltage in the trench MOSFETs. © 2015, Sumitomo Electric Industries Ltd. All rights reserved. Source

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