26 September 2022
Oxford Instruments and ITRI develop recessed-gate GaN MISHEMT
Oxford Instruments Plasma Technology (OIPT) of Yatton, near Bristol, UK and its research partner Industrial Technology Research Institute (ITRI) of HsinChu, Taiwan have announced technology developments that, they reckon, can significantly benefit key hyper-growth electric vehicle (EV), data-center and 5G markets.
The developments allow critical transistor components to operate at higher voltages (increasing performance and reliability) while also achieving a safer and more energy efficient operation (normally off E-mode) compared with existing devices. The new gallium nitride (GaN) HEMT device architecture is defined by a recessed and insulated gate junction into the aluminium gallium nitride (AlGaN) layer, i.e. a GaN MISHEMT.
In September 2021, OIPT and ITRI announced a cooperative research program for next-generation compound semiconductors. The latest breakthrough is an example of that collaboration delivering on its goal of accelerating technology to benefit the partners, their regions and wider global markets. Oxford Instruments has since also unveiled an exclusive supply deal with in-situ metrology system maker LayTec AG of Berlin, Germany, whose end-point technology is used to control the GaN MISHEMT recess gate depth. Recess depth accuracy and repeatability is critical to tune the device performance characteristics, and LayTec’s technology is designed specifically for this application, achieving target depth accuracy of ±0.5nm. ITRI provides pilot production and value-added services, including process verification and product development. OIPT says that ITRI’s integration services, especially this GaN development project, have proved beneficial, quickly proving the higher performance of the GaN MISHEMT and providing a lower risk and faster route to market for the device.
“We have excellent strategic partners and customers like Enkris, ITRI, LayTec and ROHM, and our GaN solutions are positioned strongly to serve, grow and gain from big opportunity markets,” reckons Oxford Instruments’ strategic business development director Klaas Wisniewski. “Our leading atomic layer etch (ALE) and atomic layer deposition (ALD) technology is raising material engineering performance to achieve new levels of surface quality and defect reduction, to meet the growing demand for higher-performing devices. With our technology partner ITRI, high-volume GaN manufacturing customers and our focussed investment into high-value and proprietary process solutions, we expect the GaN device market to be a key driver for our business and technology roadmap,” he adds.
“ITRI has well-established expertise and history in providing GaN HEMT manufacturing solutions that enable the global supply chain for GaN power electronics and RF applications,” says Robert Lo, deputy general director of ITRI’s Electronic and Optoelectronic System Research Laboratories (EOSL). “However, to solve the technology challenges associated with fabrication of next-generation devices, we needed more accurate and controlled technology solutions such as ALE for GaN HEMT high-volume manufacturing. Through our long-standing partnership with Oxford Instruments, we have successfully qualified and integrated their ALE solution for a recessed-gate MISHEMT into our GaN HEMT pilot-production line.”
Wisniewski presented a talk ‘Enhancing GaN HEMT Performance for Power Electronics Applications with Atomic Scale Processing Production Solutions’ at SEMICON Taiwan 2022 in TaiNEX 1, Taipei (14-16 September).