Engineered substrates technology
Subsequent growth of GaN confirms this – the final centre-to-edge bow for this 200 mm diameter wafer was 54 µm concave (figure 8), a figure that satisfies silicon industry specifications for this size wafer. Complete strain management is possible, but this requires additional oxides.
Nonetheless, given that the silicon substrate was only 750 µm in thickness, this is a very encouraging result and confirms that REO templates offer a successful route to strain engineered GaN-on-silicon.
The deployment of multiple layers of oxides for strain management and improved device performance is not limited to LEDs; this form of architecture also promises to pay dividends in GaN-on-silicon power devices (see Figure 9 for an example of both structures). REOs combine a wide bandgap with a high value of permittivity – it is greater than 12 – and may allow an in-situ gate oxide to be deposited on top of a GaN FET stack witout breaking vacuum.
Capacitance-voltage measurements show minimal hysteresis, while breakdown testing reveals a consistent breakdown voltage of 4 MV/cm.
Figure 9. Oxide-based template engineering for strain, optical and electrical enhancement of silicon based III-N wafers.
It’s clear from these results with simplified LED and transistor structures that REOs offer great promise to improve device performance and trim manufacturing costs. The range of oxides is considerable. This means that there are many avenues – some still to be explored – for taking LEDs, transistors and solar cells to new levels of affordability and performance.
© 2012 Angel Business Communications. Permission required.
RABOUTET S.A.
Manufacturer of Molybdenum. Components for MBE. Specialized Cleaning & Degassing available.
RABOUTET S.A.
250 Av Louis Armand Z.I Des Grand Prés F-74300 Cluses France Tél : 33 (0)4 50 98 15 18 Fax : 33 (0)4 50 98 92 57 E-mail :
info@raboutet.fr http://www.raboutet.fr
July 2012
www.compoundsemiconductor.net 41
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