Ka波段GaN HEMT功率器件

Ka Band GaN HEMT Power Devices

设计了Ka波段GaN功率高电子迁移率晶体管(HEMT)外延材料及器件结构,采用Al N插入层提高了二维电子气(2DEG)浓度。采用场板结构提高了器件击穿电压。采用T型栅工艺实现了细栅制作,提高了器件高频输出功率增益。采用钝化工艺抑制了电流崩塌,提高了输出功率。采用通孔工艺减小源极寄生电阻,通过优化钝化层厚度减小了寄生电容,提高了器件增益。基于国产SiC外延材料及0.15μm GaN HEMT工艺进行了器件流片,最终研制成功Ka波段GaN HEMT功率器件。对栅宽300μm器件在29 GHz下进行了微波测试,工作栅源电压为-2.2 V,源漏电压为20 V,输入功率为21 dBm时,器件输出功率为30 dBm,功率增益为9 dB,功率附加效率约为43%,功率密度达到3.3 W/mm。

The structure of epitaxial material and the device structure of GaN high electron mobility transistor（ HEMT） in Ka band were designed. The concentration of 2DEG was increased by using AlN layer. The breakdown voltage was increased by using the field plate technique. The thin gate was obtained by using T-gate process,and the power gain was increased. The current collapse was depressed by using the passivation process,and the output power was improved. The high gain of the device was achieved by optimizing the passivation layer thickness to decrease parasitic capacitance and using the via process to decrease the source resistance. Finally,the Ka band GaN HEMT power device was successfully fabricated by using domestic SiC epitaxial material and 0. 15 μm GaN HEMT process technology. At the frequency of 29 GHz the measured results of the device with 300 μm gate width exhibits an output power of 30 dBm（ 3. 3 W / mm）,power gain above 9 dB and power added efficiency（ PAE） about 43% at gate-source voltage of-2. 2 V,drain-source voltage of 20 V and input power of 21 dBm.