New manufacturing technique produces superior materials for next-gen power chips
Researchers have successfully grown high-quality semiconductor layers that match or exceed the performance of standard materials used in power electronics, using an improved manufacturing process. The advance could enable more efficient power conversion in everything from electric vehicles to data centers, while reducing production defects that currently limit device reliability.
Originaltitel: Low Al-content n-type AlxGa1-xN layers with a high-electron-mobility grown by hot-wall metalorganic chemical vapor deposition
<p>In this work, we demonstrate the capability of the hot-wall metalorganic chemical vapor deposition to deliver high-quality <em>n</em>-AlxGa1−xN (<em>x</em> = 0 – 0.12, [Si] = 1×1017 cm<sup>−3</sup>) epitaxial layers on 4H-SiC(0001). All layers are crack-free, with a very small root mean square roughness (0.13 – 0.25 nm), homogeneous distribution of Al over film thickness and a very low unintentional incorporation of oxygen at the detection limit of 5×1015 cm<sup>−3</sup> and carbon of 2×1016 cm<sup>−3</sup>. Edge type dislocations in the layers gradually increase with increasing Al content while screw dislocations only raise for <em>x</em> above 0.077. The room temperature electron mobility of the <em>n</em>-AlxGa1−xN remain in the range of 400 – 470 cm<sup>2</sup>/(V.s) for Al contents between 0.05 and 0.077 resulting in comparable or higher Baliga figure of merit with respect to GaN, and hence demonstrating their suitability for implementation as drift layers in power device applications. Further increase in Al content is found to result in significant deterioration of the electrical properties.</p>