LEUVEN (Belgium), May 7, 2019 – At PCIM 2019, imec, a world-leading research and innovation hub in nanoelectronics and digital technologies, announced today that it demonstrated a functional GaN half-bridge monolithically integrated with drivers. Mounted on a buck-convertor test board, the chip converts an input voltage of 48 Volt to an output voltage of 1 Volt, with a pulse width modulation signal of 1 MHz. The achievement leverages on imec’s GaN-on-SOI and GaN-on-QST® technology platforms, reducing parasitic inductance and boosting commutation speed.
Today, GaN power electronics are dominated by off-the-shelf discrete components. Half-bridges –common subcircuits in power systems – are fabricated by separate discrete components, either in separate packages, or integrated in one package, especially for the higher voltage ranges. Realizing half-bridges on chip by using GaN-on-Si technology, is very challenging, especially at high voltages. This is because half-bridges designed on GaN-on-Si technology are limited in performance by a back-gating effect that negatively affects the high-side switch of the half-bridge, and switching noise that disturbs the control circuits.
To unlock the full potential of GaN power technology, imec monolithically co-integrated a half-bridge and drivers in one GaN-IC chip. Complemented by low voltage logic transistors, a suite of passive components for low-ohmic and high-ohmic resistors, and a MIM-capacitor, high-end integrated power systems can be realized on one single die.
Imec’s solution builds on imec’s GaN-on-SOI and GaN-on-QST® technology platforms that allow for a galvanic isolation of the power devices, drivers and control logic, by the buried oxide and oxide-filled deep trench isolation. This isolation scheme not only eliminates the detrimental back-gating effect that negatively affects the high-side switch of the half-bridge, but also reduces the switching noise that disturbs the control circuits. With the design of a co-integrated level shifter for driving the high-side switch, a dead-time controller to avoid overlapping gate input waveforms, and an on-chip pulse-width modulation circuit, highly integrated buck and boost convertors can be fabricated.
“Someone might think that by using SOI or QST® wafers instead of Si wafers will result in more expensive technology. However, with GaN-on-Si several discrete devices need to be individually packaged (with advanced packages to take advance of the GaN fast switching performance) and connected to their drivers and other elements at the board or packaged level”, stated Denis Marcon, business development manager at imec. “Instead, with imec’s GaN-IC technology, the full converter including drivers and analog blocks etc. is on-chip, which can then be packaged with simple package technology (as the frequency sensitive components are already connected on-chip). This dramatically saves on the cost of the final power system.”
To further boost the performance of these monolithic integrated power systems, imec aims to extend its platform with additional co-integrated components, such as Schottky diodes and depletion-mode HEMTs.
“With the aim to further foster innovation in the GaN power electronics, this GaN-IC platform is available for prototyping through our multi-project-wafer (MPW) service”, commented Stefaan Decoutere, program director GaN power electronics at imec. “The possibilities for high-end power systems with unprecedented performance, either in switching speed, operating frequency or energy efficiency, with reduced inductive parasitics and unseen reduction of the form-factors, will further boost the use of GaN for power supplies in the consumer and re-useable energy market segments.”
Imec is a world-leading research and innovation hub in nanoelectronics and digital technologies. The combination of our widely acclaimed leadership in microchip technology and profound software and ICT expertise is what makes us unique. By leveraging our world-class infrastructure and local and global ecosystem of partners across a multitude of industries, we create groundbreaking innovation in application domains such as healthcare, smart cities and mobility, logistics and manufacturing, energy and education.
As a trusted partner for companies, start-ups and universities we bring together more than 4,000 brilliant minds from over 97 nationalities. Imec is headquartered in Leuven, Belgium and has distributed R&D groups at a number of Flemish universities, in the Netherlands, Taiwan, USA, and offices in China, India and Japan. In 2018, imec’s revenue (P&L) totaled 583 million euro. Further information on imec can be found at www.imec-int.com.
During the last decades, EUROPRACTICE has been supporting customers with design tools and easy access to low-cost prototyping and small volume fabrication in ASIC, MEMS and photonics technologies. EUROPRACTICE also supports the training of future generations of engineers that is required for the growing digital economy in Europe.
The current service is being offered by IMEC (B), STFC-UKRI (UK), Fraunhofer IIS (D), CMP (FR) and TYNDALL (IRL).
As part of a new European grant, the existing services will be complemented and extended by adding new technologies to serve new markets, diversifying the service towards smart system integration and encouraging new users from non-traditional sectors.