S波段脉冲大功率SiC MESFET

采用自主开发的3英寸(75mm)SiC外延技术和SiC MESFET的设计及工艺加工技术,成功地实现了S波段中长脉宽条件下(脉宽300μs,占空比10%),输出功率大于200W,功率增益大于11dB,功率附加效率大于30%的性能样管,脉冲顶降小于0.5dB,实现了大功率输出条件下的较高功率增益和功率附加效率及较小的脉冲顶降,初步显示了SiC功率器件的优势。器件设计采用多胞合成技术,为减小引线电感对功率增益的影响,采用了源引线双边接地技术;为提高器件的工作频率,采用了电子束写栅技术;为提高栅的可靠性,采用了加厚栅金属和国家授权的栅平坦化发明专利技术;同时采用了以金为主体的多层难熔金属化系统,提高了器件的抗电迁徙能力。

S-Band High Power SiC MESFETs for Pulse Operation

The internally-matched MESFETs for S-band operations were fabricated by own epitaxial structure on 4H-SiC and SiC MESFETs technology.The test was realized at a frequency of 2 GHz with a pulse width of 300 μs and 10% duty cycle.The results show that the output power is over 200 W with the power gain over 11 dB,the power added efficiency is over 30%,and the power droop is less than 0.5 dB.In the research,the dual-grounded source contacts were utilized to decrease the effect of the inductance on the power gain.The gate patterns were defined by electron beam etching to improve the frequency properties.The thick gate metal and the patent of the gate planarization were adopted to improve the reliability of the gate.And the multilayer refractory metal system was used to prevent the metal electro migration.In the end,the high power SiC MESFETs with high power gain,high efficiency and little power droop were fabricated.