news digest ♦ Power Electronics
With the new system, SDK will extend its existing 100mm-diameter wafer production and also migrate production to the larger diameter 150mm SiC wafers that are now becoming available from semiconductor material suppliers. Production on larger wafers should lead to cost reductions and wider market acceptance.
“Aixtron has designed its system to push these economies of scale even further by reducing the wafer edge exclusion zone, increasing chip yields per wafer of larger diameter substrates,” Frank Wischmeyer, Vice President and Program Manager Power Electronics at Aixtron, comments. “The attraction of silicon carbide for such application derives from its unique material properties, such as high critical electrical field strength, allowing high device breakdown voltages and low turn- on resistance. Further advantages for power applications arise from SiC’s higher thermal conductivity and ruggedness at higher operation temperatures.”
A special reactor chamber was developed for the most modern Aixtron Warm-Wall reactor for SiC. It is capable of handling up to the 1650°C, which is needed for the growth of SiC. The six 150mm wafers loaded per batch in the Aixtron system have individual ‘planetary’ rotation during epitaxy, to improve uniformity and reproducibility.
The company sees market opportunities for SiC- based products arising immediately in consumer electronics, and in the longer term in railroad power handling and automotive markets.
The epitaxial SiC business was acquired at the end of 2008 from Esicat-Japan LLP, a spin-off from Japan’s National Institute of Advanced Industrial Science and Technology (AIST), Central Research Institute of Electric Power Industry (CRIEPI) and Showa Denko.
When compared with conventional silicon-based semiconductors, SiC power devices using SiC epitaxial wafers can operate under higher voltages, heavier currents and at higher temperatures.
These features enable reductions in the number of components and miniaturisation of cooling devices, helping to make smaller and lighter power control modules. SiC power devices also reduce energy loss in the process of power control, resulting in a
114
www.compoundsemiconductor.net October 2012 substantial energy saving.
Schematics of SBD and MOSFET, based on SiC epitaxial wafers
SiC power devices are also expected to be used increasingly in inverters (devices for converting direct current into alternating current) to control rotation of motors. Such inverters are already commercialised in some home electric appliances and distributed power supply systems, and used in subway railcars on a trial basis.
Outline of products related to SiC epitaxial wafers
What’s more, an increasing number of electric vehicles and hybrid cars are expected to be equipped with inverters using SiC power devices. These inverters contain Schottky barrier diode (SBD), and metal oxide semiconductor field-effect transistors (MOSFETs), based on SiC power devices.
SDK says it can manufacture SiC-MOSFETs, incorporating a surface oxide film which is very smooth. The smooth surface is needed during device operation.
Following the capacity expansion, SDK will continue developing SiC epitaxial wafers with larger diameter, lower defect, and higher uniformity. The firm will concentrate on developing six-inch SiC epitaxial wafers for heavy-current high-voltage applications.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131