美科学家利用氩离子植入将氮化镓组件击穿电压升至1,650V

氮化镓(Gallium nitride， GaN)被视为制作高功率电子组件的新一代材料，但到目前为止该材料都受到约略高于250V的击穿电压(breakdown)所苦；美国北卡罗来纳州立大学(North Carolina State University)的研究人员表示，他们已经找到一种方法可将氮化镓组件击穿电压提升至1,650V，并因此可让其功率承受能力(power handling)提升十倍。

具备高功率承受能力的氮化镓组件将可适用许多新兴领域，包括智能电网(smart-grid)与电动车。北卡罗来纳州立大学教授Jay Baliga表示，他们是沿着氮化镓组件的终端电极(termination electrode)植入中性物种(neutral species)——氩(argon)，其电场(electrical fields)就会被散布开来，并因此避免崩溃电压过早发生(参考下图)。Baliga是与该校在读博士生Merve Ozbek合作进行以上研究。

研究人员利用在氮化镓组件的终端电极进行离子植入(绿色部分)，将该类组件的击穿电压从300V提升至1,650V

“高压功率组件的最大问题，是其边缘会过早出现击穿电压；我们为氮化镓组件开发出一种新的平面式(planar)边缘终端电极技术，利用氩离子植入在组件边缘制作一片薄薄的非晶层，达到近乎理想化的平面化平行击穿电压。”Ozbek表示：“植入物在二极管组件边缘的表面形成了薄薄的高电阻区域，有助于分散组件边缘表面的电位(potential)，并降低电场。”

研究人员是以氮化镓制作肖特基二极管来测试新研发的技术，并将其击穿电压成功地提升到1,650V、近乎原来的七倍；因此也让该氮化镓组件的电阻率降低了100倍，让其功率承受能力增强了十倍。

翻译：Judith Cheng

点击进入参考原文：Gallium nitride boosted into high-power realm

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Gallium nitride boosted into high-power realm

R. Colin Johnson

Gallium nitride is lauded as the next-generation material for high-power electronics, but until now has been plagued by breakdown above about 250 volts, according to researchers at North Carolina State University. The researchers claim to have discovered a technique to raise breakdown to 1,650 volts, thereby boosting power handling by 10 times.

These high-power handling GaN devices will be useful for emerging applications ranging from smart-grid to electric cars.

By implanting a neutral species—argon—alongside its termination electrode (see figure) the electrical fields are spread out, thereby preventing premature breakdown, according to professor Jay Baliga, who performed the work with doctoral candidate Merve Ozbek.

"One of the major problems of high voltage power devices is pre-mature breakdown at its edges. Our work demonstrates a novel planar edge termination technique for GaN devices with which nearly ideal plane parallel breakdown voltages can be achieved by creating a thin amorphous layer at the edge of the device by using argon ion-implantation," said Ozbek. "The implantation creates a thin high resistivity region at the surface beyond the edges of the diode which promotes the spreading of the potential along the surface reducing the electric field."

The researchers tested their technique by fabricating Schottky diodes, raising their breakdown voltage by almost seven times to 1,650 volts. As a result, the electrical resistance of the devices was reduced by 100-times, thereby allowing the 10-fold boost in power handling capabilities.