GaN-on-Silicon

We're happy to interview ALLOS Semiconductors, as part of our new series of interviews with MicroLED Industry Association members. ALLOS Semiconductors is an IP licensing and technology company that focuses on GaN-on-Si technology for the microLED industry. ALLOS offers a turn-key technology transfer to establish a super-uniform CMOS-compatible large epiwafer process at customers within only 12 weeks.

Q: Hello! Can you introduce your company and technology?

ALLOS Semiconductors is the global leader for gallium nitride on silicon epiwafer technologies (GaN-on-Si) for next generation, micro LED-based display solutions and other applications building on more than 20 years track-record.

Image

Our customer and partner base includes top-tier companies from the electronic device, display, LED and semiconductor foundry industries. They benefit from the cost, yield and performance advantages of our patent-protected 200 and 300 mm GaN-on-Si micro LED epiwafer technologies – including our unique 1 bin® technologies.

Kyocera Corporation announced that it has successfully developed a new process technology to produce microLED (and micro-laser) devices. The process is based on lateral growth of GaN layer on a silicon wafer, in a way that limits defects in most of the area.

Image

The basic process has three steps. First you grow a GaN layer on silicon. The second step is to apply a mask with a has a horizontal gap. The third step is to continue growing the GaN layer. The defects are concentrated in the opening nucleus, but the rest of the growth area remains almost defect free. The actual microLED devices are fabricated from the low-defect region.

China-based GaN epiwafer producer Enkris Semiconductor launched new microLED epiwafers. The "Full Color GaN" series offers GaN-on-Si microLED epiwafers, with wafers sizes of up to 300 mm.

Enkris' new epiwafers offers blue, red and green LED arrays, all based on the same material platform. Enkris Semiconductor uses its patented strain engineering and polarization engineering, which it says is unique, to expand its GaN-on-Si LED epiwafer product portfolio to all colors (with wavelengths of 390-650nm).

Hong Kong based microLED microdisplay developer Raysolve Technology announced that it raised $10 million USD in its Pre-Series A Financing Round. The funding will be used to scale up its R&D activities and initiate production of its first microdisplays.

In the last 6 months, Raysolve raised almost $15 million from an angel investor (Source Code Capital) and VCs. This new funding round was led by Gaorong Capital along with Glory Ventures.

Porous-GaN material platform developer Porotech raised £3 million as it accelerates its microLED production technology development.

Porotech developed a new class of porous GaN semiconductor material, which according to the company offers performance improvements over current materials. In November 2020, the company announced what it says is the first commercial native red LED epiwafer for micro-LED applications.

Global digital signage solution provider STRATACACHE is constructing the first US-based complete display production facility in Eugene, Oregon. The future MicroLED E4 fab is planned to commence production in 2022, and the fab will be a complete microLED production line, from epiwafer (on 300 mm silicon wafers), through transfer process and to final module assembly.

This project is extremely interesting, and we set out to discuss it with STRATACACHE's founder and CEO, Chris Riegel. At STRATACACHE, Chris leads strategic direction, technology development and engineering operations, and the MicroLED fab project seems to be personally spearheaded by him.

Global digital signage solution provider STRATACACHE is embarking on a project to construct a microLED display production line in Eugene, Oregon. The company aims to start production in this fab at around 2022-2023, with plans to adopt these microLED displays in its own solutions.

The new factory (E4) will be a complete microLED production line, from epiwafer (on 300 mm silicon wafers), through transfer process and to final module assembly. The company plans to produce a wide range of displays, from tablet-sized panels to large-area displays. Some of these displays will be flexible and transparent as the company sees a market demand for such technologies. The yearly capacity of the E4 is expected to start at a 1 million square meters per year.

France-based 3D GaN LED developer Aledia announced that it plans to establish a 140 million euros LED production fab in Champagnier, near Grenoble in France. The plan is to start LED production by 2022 - and by the company will also finalize its microdisplay production process and will start offering microLED microdisplays.

Aledia developed a microLED production process, based on a unique 3D architecture using GaN-on-silicon nanowires (branded as WireLED).

GaN-on-Si IP developer ALLOS Semiconductors announced it is collaborating with with Prof. Ohkawa and his team at King Abdullah University of Science and Technology (KAUST) to develop high efficiency nitride-based red LEDs on large diameter silicon substrates.

Prof. Ohkawa and team have developed an indium gallium nitride (InGaN)- based red LED stack with low forward voltage of less than 2.5 V and high efficiency by using local strain compensation and a modified MOCVD reactor design. ALLOS and the KAUST team will combine their unique technologies to handle strain and optimize crystal growth conditions for GaN-on-Si and red LEDs. To this end, the KAUST team will grow its red LED stack on top of ALLOS’ GaN-on-Si-buffer layers, which will be fine-tuned during the collaboration to optimize the performance of KAUST’s red LED stack.

German-based GaN-on-Si developer ALLOS announced that it has sold its high-power electronics and RF business to AZUR SPACE. ALLOS will now focus its business on the microLED display market.

ALLOS Semiconductors developed its GaN-on-Si epiwafer technology for both high power electronics and Micro LED applications, but the time has come to focus on one market. The company says its 200 and 300 mm epiwafer technology is crucial in meeting the uniformity, crystal quality and manufacturability requirements of the novel Micro LED display applications.