GaN Goes Green: Three Ways GaN Is Good for the Planet
GaN isn't just a good choice for high-frequency designs. It's also good for the planet, according to a recent report.
Wide-bandgap semiconductors (WBG) have shot skyward in popularity for power electronics. Enabling high power efficiency and small sizes, wide-bandgap semiconductors are often posed as a key tool to achieve a carbon-neutral future.
Low on-resistance and fast switching speeds make GaN a good fit for high-frequency performance. Image (modified) used courtesy of ROHM Semiconductor
Of all the WBG semiconductors, gallium nitride (GaN) seems particularly well-suited for a greener future. Earlier this year, Navitas Semiconductor published its first annual GaN sustainability report, highlighting the many ways in which GaN can enable environmentally-friendly electronics.
Here are three ways GaN has been found to optimize power designs to decrease the carbon footprint of high-frequency devices and systems.
1. Energy Efficiency
One of the major draws of GaN is that it is a much better semiconductor than silicon, offering higher electron mobility and, subsequently, lower RDS(on). GaN offers an electron mobility of almost 1,000 times that of conventional silicon, making it significantly more power efficient than its silicon counterpart.
Increased efficiency also means that GaN devices don’t generate as much heat. Because GaN devices operate at lower temperatures, they often don't require heatsinks or energy-hungry active cooling systems in server racks or power supplies.
2. Reduced Manufacturing Emissions
Beyond energy savings, GaN benefits the environment by reducing emissions and raw materials needed in the manufacturing process.
GaN power ICs require less CO2 emissions per unit. Image used courtesy of Navitas Semiconductor
Since GaN offers such high efficiencies, the essential die size needed for a given application is much smaller for a given power or current capability compared to silicon. Requiring smaller chips for the same performance means more units per wafer, better use of resources, and an overall lower per-chip footprint for the same amount of energy—which equates to less CO2 and chemicals used in wafer processing. According to Navitas, in 2020 a GaN power FET had a four-times reduction in CO2 versus a legacy silicon FET.
3. Reduced Materials
Finally, beyond lower on-channel resistance, GaN offers designers the ability to switch at extremely high frequencies.
Historically, silicon-based power electronics yield an inversely proportional relationship between switching frequency and system efficiency: as switching frequency increases, system efficiency decreases. This is generally because the reverse recovery loss of a traditional silicon FET serves as a non-negligible source of loss in the system.
GaN devices are able to achieve higher efficiencies at high switching rates. Image used courtesy of KEMET
GaN changes this narrative, however, by eliminating the reverse recovery loss, meaning that it can maintain high levels of power efficiency even at extremely high frequencies. The important corollary of this is that high switching frequencies mean that the external passive components in these systems can be much smaller.
Smaller passives mean that GaN-based systems elicit smaller housings, less overall material, reduced manufacturing costs, and low shipping costs.
A Green GaN Future
In more ways than one, GaN is uniquely positioned to enable a greener, more carbon-neutral future for the electronics industry. Some semiconductor companies are even using GaN's lower environmental impact as a value proposition. ROHM, for instance, recently introduced a new series of 150 V GaN HEMTs that fall under the umbrella of the company's "EcoGaN" devices. These devices aim to conserve energy and miniaturize devices by capitalizing on GaN's high switching speeds and low ON resistance.
With higher power efficiencies, miniaturized electronic systems, and decreased manufacturing emissions, GaN may be yet another way to combat the global e-waste battle.