Telecoms ♦ news digest
this up-scaling. Usually, the collector dopants are introduced in the beginning of the processing and thus exposed to the complete thermal budget of the process flow.
This complicates the accurate positioning of the buried collector. By in-situ arsenic doping during the simultaneous growth of the sub-collector pedestal and the SiGe:C base, imec introduced both a thin, well controlled, lowly doped collector region close to the base and a sharp transition to the highly doped collector without further complicating the process. This resulted in a considerable increase of the overall HBT device performance: Peak fMAX values above 450GHz are obtained on devices with a high early voltage, a BVCEO of 1.7V and a sharp transition from the saturation to the active region in the IC-VCE output curve.
Despite the aggressive scaling of the sub-collector doping profile, the collector-base capacitance values did not increase much. Moreover, the current gain is well defined, with an average around 400 and the emitter-base tunnel current, visible at low VBE values, is limited as well.
Compound semiconductors are a priority for Sumitomo Chemical
The firm has strengthened its compound semiconductor materials business to cope with demand for high frequency devices which use gallium arsenide and gallium nitride epiwafers.
Sumitomo Chemical will expand its facilities for production of compound semiconductor materials at the Chiba Works (Sodegaura, Chiba Prefecture) to further strengthen this business and enhance a stable supply of these materials to customers.
GaAs-based compound semiconductors are widely adopted for high-frequency devices used in mobile phones and other equipment because of their outstanding signal processing at high frequencies and low power consumption. In recent years, demand has been growing rapidly for applications for antenna switches and power amplifiers used in multifunction mobile phones typified by smartphones.
As such, demand is expected to continue to increase in the future. Compound semiconductor materials for which the Company will expand production are GaAs epiwafers prepared by thin film crystal growth of materials, such as GaAs, on GaAs substrates.
Up to now the company has been manufacturing GaAs epiwafers at the Chiba Works and Sumika Electronic Materials, its US subsidiary, with production capacity expanded stepwise in the past. Given expectations of a continued increase in demand for GaAs epiwafers, the Company has decided to double the compound semiconductor materials production capacity at the Chiba Works with an investment of about US $52 million for the purpose of establishing a fully secured system for stable supply as well as expanding the business.
In addition, capitalising on its technology cultivated through the GaAs epiwafer business, Sumitomo Chemical is engaged in the development of new compound semiconductor materials. Specifically, the Company will participate in the government- private sector joint project for next generation power semiconductors at the Nagoya Institute of Technology where it undertakes R&D on GaN, one of the next generation power semiconductor materials.
Next generation power semiconductors are capable of being operated at high voltage and high temperatures. They are expected to contribute to the improved performance of home electrical appliances and personal computers, as well as electric vehicles, solar cells, and other equipment for wind power or geothermal power generation, areas likely to show market expansion in the future. Also, these semiconductors are believed to contribute to energy saving.
Positioning the compound semiconductor materials business as one of the priority areas of the IT- related Chemicals Sector, the Company will enhance existing operations through this expansion of production capacity as well as to seek to further expand its business by focusing efforts on the development of new materials.
November/December 2011
www.compoundsemiconductor.net 133
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 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176 |
Page 177 |
Page 178 |
Page 179 |
Page 180 |
Page 181 |
Page 182 |
Page 183 |
Page 184 |
Page 185 |
Page 186 |
Page 187 |
Page 188 |
Page 189 |
Page 190 |
Page 191 |
Page 192 |
Page 193 |
Page 194 |
Page 195 |
Page 196 |
Page 197 |
Page 198 |
Page 199 |
Page 200 |
Page 201 |
Page 202 |
Page 203 |
Page 204 |
Page 205 |
Page 206 |
Page 207 |
Page 208 |
Page 209 |
Page 210 |
Page 211 |
Page 212 |
Page 213 |
Page 214 |
Page 215 |
Page 216 |
Page 217 |
Page 218 |
Page 219 |
Page 220 |
Page 221 |
Page 222 |
Page 223 |
Page 224 |
Page 225 |
Page 226 |
Page 227 |
Page 228 |
Page 229 |
Page 230 |
Page 231 |
Page 232 |
Page 233 |
Page 234 |
Page 235 |
Page 236 |
Page 237 |
Page 238 |
Page 239 |
Page 240 |
Page 241 |
Page 242 |
Page 243 |
Page 244 |
Page 245 |
Page 246 |
Page 247 |
Page 248 |
Page 249 |
Page 250 |
Page 251 |
Page 252 |
Page 253 |
Page 254 |
Page 255