Researchers at EPFL have presented an intrinsic polarization superjunction (iPSJ) GaNgallium nitrideGaN is another material platform mentioned for use in different power delivery roles. transistor that combines very high blocking capability with low resistance. Built from GaNgallium nitrideGaN is another material platform mentioned for use in different power delivery roles. layers on a low-cost silicon base, the device reportedly withstands nearly 4 kV before breakdown, which the team describes as a record for this transistor class.
The key mechanism is the use of GaNgallium nitrideGaN is another material platform mentioned for use in different power delivery roles.’s natural polarization. By engineering the layer thickness so that positive and electron charge sheets balance each other, the device avoids the charge imbalance that limits conventional GaNgallium nitrideGaN is another material platform mentioned for use in different power delivery roles. transistors to roughly 600–650 V. When the transistor turns off, charge does not accumulate locally, so the voltage spreads more evenly along the channel. The design also removes the need for chemical doping.
A second result addresses p-type GaNgallium nitrideGaN is another material platform mentioned for use in different power delivery roles. contacts. Researchers lowered the contact resistivity to (1–3) × 10⁻⁴ Ω cm² by depositing an ultrathin magnesium layer on p-GaNgallium nitrideGaN is another material platform mentioned for use in different power delivery roles. and briefly annealing at 600°C. Compared with thicker Mg films, the thin layer produced a smoother surface after annealing. Although magnesium oxidizes easily in air, the study found that a protective cap did not materially change the outcome.
In the soft-anneal process, magnesium rapidly diffuses into the near-surface region, forming an ultrahigh-concentration doped layer that narrows the contact depletion region and supports hole tunneling. The method is simpler and faster than bottom-up crystal growth and can be applied after device processing. The team says the approach is now being extended to LEDlight-emitting diodeSemiconductor diode that emits light when current flows.s and power transistors for EVs.
On the thermal side, MIT, Georgia Tech and Penn State embedded GaNgallium nitrideGaN is another material platform mentioned for use in different power delivery roles. transistors in an ultrathin single-crystal diamond interposer. The process uses femtosecond-laser-drilled cavities in diamond, die attach film, and subsequent dielectric and metal stacking. The diamond layer acts as a heat spreader that evens out temperature across the structure and allows the GaNgallium nitrideGaN is another material platform mentioned for use in different power delivery roles. devices to run near peak performance without sacrificing reliability. The group demonstrated the method in a power amplifier for wireless communications.