ALLOS’ customers confirm dynamic on-resistance of carbon-doping-free GaN-on-Si

In an invited talk at the 2018 European Materials Research Society (E-MRS) Fall Meeting at Warsaw University of Technology, Poland, Dr Atsushi Nishikawa, the co-founder & chief technology officer of IP licensing & technology engineering firm ALLOS Semiconductors GmbH of Dresden, Germany, showed data from customers that confirms not only outstanding wafer-level data but also what is claimed to be excellent dynamic on-resistance (Ron) and high-temperature performance for its gallium nitride on silicon (GaN-on-Si) epitaxial material. Most importantly, carbon-doping (known for causing bad dynamic on-resistance) is uniquely avoided.

Being able to prove this is important for the high-power electronics (HPE) industry because it confirms the widespread belief that the absence of C-doping can help to reduce switching losses at high frequencies (dynamic Ron) by reducing electron-trapping effects, says ALLOS. Nevertheless, C-doping is usually unavoidable to achieve the required breakdown voltage but it causes lower crystal quality and, with that, more trapping and reliability issues.

ALLOS has therefore overcome this challenge of delivering other crucial performance parameters at the same time by showing - on the same epiwafer - not only good dynamic Ron but also the good crystal quality and extremely low leakage of ALLOS’ material. “In epitaxy you often need to work with trade-offs between different criteria and thus it is really a big success to achieve all required specification parameters at the same time,” says Nishikawa.

“It is ALLOS’ value proposition to deliver a technology platform addressing all required spec parameters at the same time to enable our customers to make such epiwafers themselves after a technology transfer from us in only 12 weeks,” notes co-founder & chief marketing officer Alexander Loesing.

Figure: Relationship of critical electric field and dynamic on-resistance (black data points are from Würfl et al., IEDM 13-144 (2013)).

In addition to excellent dynamic Ron and leakage performance, the 150mm and 200mm epiwafers have controlled and flat bow and - through availability in SEMI-standard thicknesses - the epiwafers are suitable for processing in high-volume CMOS lines.

Based on its business model, ALLOS continues making its epiwafer technology available to high-power electronic companies that would like to enter the GaN-on-Si sector and avoid the cost, risk and uncertainty of starting their own epi development from scratch. “At the same time, also customers who already have an ongoing GaN-on-Si activity can benefit. In some cases they are not yet completely happy with their performance or want to increase the voltage range of their products to 1200V,” says Loesing. He further cites that, in particular, wafer breakage is a key problem still faced by many. “And of course customers can test the technology easily by buying epiwafer samples from us,” he adds, focusing on the low risk that ALLOS offers by guaranteeing the performance delivered in a technology transfer.

See related items:

IEMN demonstrates over 1400V breakdown on ALLOS’ new GaN-on-Si epi

ALLOS challenges conventional beliefs of GaN-on-Si

ALLOS' doping-free 600V HEMT epi technology running on both Aixtron G5 and Veeco K465i at customer

ALLOS transfers GaN-on-Si power semiconductor epi technology to customer

Tags: Azzurro GaN-on-Si MOCVD

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