GaN: Excelling in the extreme
Eradicating a high defect density in GaN epilayers will allow devices to shine in extreme environments, where they are adept at withstanding high temperatures, corrosive materials and bombardment from radiation.
BY SAVANNAH EISNER, JESSICA FRICK AND DEBBIE SENESKY FROM STANFORD UNIVERSITY
Thanks to its remarkable properties, GaN is now a mainstay material for power and RF electronics. Its cherished strengths are its high breakdown voltage, and its high values for the mobility and the carrier saturation velocity of its two-dimensional electron gas (2DEG) channel. But what makes this material even more remarkable is that it combines these attributes with a tolerance to high temperatures and a tremendous resistance to radiation attack – it is these attributes that make GaN a very attractive material for expanding the Internet of Things (IoT) into extreme environments.
This particular promise has not gone unnoticed, with researchers already starting to explore GaN as a platform for long-range IoT communication technology in space exploration applications, as well as medium-range IoT communication technologies in terrestrial applications requiring computation, timing, and sensing within hostile conditions. There are emerging opportunities for GaN associated with geothermal, oil and gas, and hypersonics.
GaN can be harnessed for all of these opportunities because silicon, the dominant semiconductor of choice for many decades, exhibits poor performance in extreme environments. Since its invention in 1954, the scope of the silicon transistor has been fundamentally limited to benign environments.