蓝宝石衬底AlGaN/GaN HFET功率特性

Output Power of an AlGaN/GaN HFET on Sapphire Substrate

通过台面隔离与注入隔离结合的方法,解决了由于GaN外延材料缓冲层质量差造成的AlGaN/GaN HFET击穿电压低的问题.通过优化的500℃/50s栅退火条件,改善Ni-AlGaN/GaN二极管特性,理想因子和势垒高度分别优化到1.5和0.87eV.通过改进AlGaN/GaN HFET制备工艺,得到提高器件输出功率的优化工艺,采用这一工艺制备的蓝宝石衬底总栅宽为1mm,器件在频率为8GHz时输出功率达到4.57W,功率附加效率为55.1%.

The low breakdown voltage of AlGaN/GaN HFETs,which is caused by the poor buffer layer of GaN epitaxial wafer,is improved through mesa isolation and implantation isolation. Annealing at 500℃ for 50s after the gate metal deposition yields the best performance for an Ni-AlGaN/GaN diode. In particular,the ideality factor and barrier height reach 1.5 and 0. 87eV, respectively. Optimization is achieved by comparing the performance of the gate and output power of AlGaN/GaN HFETs fabricated under different conditions. The output power of a 1mm-gate-wide AlGaN/GaN HFET on sapphire substrate is 4. 57W, with a power added efficiency of 55.1% at 8GHz.