7 October 2020
Picosun’s cluster ALD solutions enable next-generation power electronics
Picosun Group of Espoo, Finland, the leading supplier of AGILE ALD (atomic layer deposition) thin-film coating solutions for global industries, has strengthened its position in power electronics market with several cluster ALD system sales to prominent manufacturers in Europe, USA and Asia.
“Power electronics is an important, fast-growing market for Picosun. ALD has potential to solve various challenges manufacturers are facing in this field, and our solutions have enabled our customers to create significant added value in terms of device quality and throughput,” says Juhana Kostamo, head of Customer Solutions/deputy CEO of Picosun. “At Picosun, we have developed several turn-key production ALD solutions specifically for 4-8 inch wafer markets such as power devices. Especially our cluster ALD systems, such as the PICOSUN Morpher which we launched last year, have been extremely well received by our customers.”
Power components are crucial in a wide range of applications from consumer electronics to transportation, energy production and distribution, including renewables such as wind and solar power generation. These components are typically manufactured on 4-8 inch compound semiconductor wafers such as gallium nitride (GaN) and silicon carbide (SiC). These materials provide various benefits compared with pure silicon, for example higher electron mobility, higher threshold voltage, and ability to operate at higher temperatures. Challenges do exist, however, as GaN and SiC power devices are prone to high interface trap density (leading to parasitic currents and reduced electron mobility) and gate leakage current, and poor threshold voltage stability.
Interface trap density can be reduced by combining pre-cleaning methods with high-permittivity, large-bandgap insulators. High-quality, defect-free high-k dielectric layers such as Al2O3, AlN or ZrO2 etc are key in reducing power devices’ gate leakage current and to improve electron mobility and threshold voltage stability. A good example here is GaN-based HEMTs (high-electron-mobility transistors), which are important in various large-scale practical applications, and which require efficient gate insulation and surface passivation to achieve optimal functionality.
Picosun says that ALD stands as a superior deposition method here compared with other thin-film coating technologies such as PECVD (plasma-enhanced chemical vapor deposition) as ALD produces the most conformal, uniform and defect-free films with accurate, digitally repeatable thickness control and sharp interfaces. With the right selection of ALD deposition equipment, even multi-layer processing is possible, i.e. various functional material layers and/or stacked films/nanolaminates can be manufactured in one process run.
PICOSUN Morpher is a disruptive ALD production platform designed for up to 8-inch wafer industries such as power electronics, MEMS, sensors, LEDs, lasers, optics and 5G components. Morpher’s operational agility makes the system adaptable to various and changing manufacturing needs, on all business verticals from corporate internal R&D to production and foundry manufacturing, where both the end products and/or customers’ requirements may change rapidly. Morpher can handle several substrate materials, batch and substrate sizes, and ALD materials with leading process quality. Multi-layer deposition is possible, and cluster design allows integration also of other processing units such as pre-clean, RIE (reactive on etch) etc for fully automated, high-throughput continuous vacuum operation.
“In its versatility and transformability, Morpher is the epitome of our principle ‘Agile ALD’,” says Kostamo. “Innovation, constant development and improvement of our ALD solutions to enable our customers’ success is our driving force at Picosun,” he adds. “This applies also to the Morpher platform and we have some truly exciting additions to this product family coming in the near future.”