Automated inspection tool to unveil defects in raw Gallium Nitride (GaN) and Silicon Carbide (SiC) crystals.

Informations projet

GaNSpector

N° de convention de subvention: 101033102

DOI

10.3030/101033102

Projet clôturé

Date de signature de la CE 24 Mars 2021

Date de début 1 Avril 2021

Date de fin 31 Mars 2023

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total

€ 191 149,44

Contribution de l’UE

€ 191 149,44

Coordonné par

SCIENTIFIC VISUAL SA
Switzerland

Periodic Reporting for period 1 - GaNSpector (Automated inspection tool to unveil defects in raw Gallium Nitride (GaN) and Silicon Carbide (SiC) crystals.)

Période du rapport: 2021-04-01 au 2023-03-31

Résumé du contexte et des objectifs généraux du projet

Gallium Nitride (GaN) and Silicon Carbide (SiC), in particular the 4H hexagonal polytype of SiC (4H-SiC), are wide bandgap semiconductors with significantly superior electrical and thermal characteristics compared to Silicon.
Both materials are key enablers for ongoing changes in electric utility and transportation infrastructures. Commercial products that significantly benefit from GaN and 4H-SiC semiconductors include solid-state energy converters, power management electronics, power amplifiers, light-emitting diodes, displays, solar cells, lasers, environmental sensors and potential for 5G technology. The high defectiveness of produced crystals is one of the principal obstacles to expanding GaN and 4H-SiC use.
1. The crystal growth process is challenging to control in-situ in real-time,
2. Today the defect identification takes place after time-consuming crystal wafering and polishing procedure. It means that initially defective areas are wafered and polished and then rejected by downstream quality control. The industry will greatly benefit from a non-destructive quality control tool, that could indicate defective regions of crystals “on-the-spot” to avoid its costly processing and, consequently, reduce the fabrication costs.
This project aimed to develop an automated non-destructive inspection tool to help semiconductor manufacturers to get insight into raw GaN and 4H-SiC crystal quality. Such a scanner will help improving the growth process and assessing the defectiveness of GaN and 4H-SiC crystals before processing. It will save resources on slicing and polishing initially defective crystals, and thereby time and costs to fabricate epi-ready wafers, as well as reduce the environmental impact.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

The project was divided into four stages with milestones and deliverables.

Stage 1 (April 2021 - September 2021) focused on establishing a proof of concept, including literature search, conference online attendance (ASMC online, https://www.semi.org/en/news-media-press/semi-press-releases/virtual-asmc-2021 and CSMantech Virtual 2021, https://csmantech.org/conference/2021/) testing of GaN samples in one of the existing scanner, assembling and testing a fully operational laboratory set-up, and webpage creation (https://scientificvisual.ch/gan/ https://scientificvisual.ch/sic/).
This stage was successfully concluded with:
Milestone M1: Demonstration of defect visualization of GaN non-intentionally doped crystal using selected radiation source and sensor combination.
Deliverable D1: Acquisition of internal images of GaN crystal as a proof of concept.

Stage 2 (October 2021 - January 2022) involved developing a laboratory prototype, including testing of GaN and 4H-SiC crystals in two of our inspection systems, exploring microscopy and inspection techniques, identifying a new measurement technique, updating webpages, and engaging with prospective customers.
This stage was successfully concluded by:
Milestone M2: Demonstration of scans resolving internal defects and mapping their position in 3D.
Deliverable D2: Minimum Viable Product (MVP). First demonstration to prospective clients.

Stage 3 (February 2022 - September 2022) focused on building an industrial prototype, including contacting manufacturers, defining software functionalities, adjusting the prototype, conducting measurements, and participating in communication events (IWCGT-8, Berlin, https://iwcgt-8.ikz-berlin.de/ ECCG7, Paris, http://www.escg3-eccg7-paris2022.insight-outside.fr/ ICSCRM2022, Davos, https://icscrm2022.org/).
This stage was successfully accomplished with:
Milestone M3: First letters of intent from prospective clients
Deliverable D3: The development of two industrial prototypes of GaN/SiC inspection systems that are stable, and ready to be customized for the prospective clients.

Stage 4 (October 2022 - March 2023) was dedicated to commercialization, including further software development, adaptation of the tool to other crystals, participation in industrial fairs (Semicon Europa 2022 industrial fair, Munich, https://www.semiconeuropa.org) and events (European Researchers' Night 2022 event online, Science is Wonderful! event in Brussels), completion of IP courses from WIPO, and patent application for a CRYSTAL WAFERING SYSTEM AND METHOD (“Smart Wafering” see image below).
Milestone 4 (Patent application is assessed and filed. Trademark registration is filed.) and Deliverable 4 (Industrial version of the tool certified and commissioned for client) could not be completed due to delay in assessing the prototypes capability.
In particular, the certification process involves rigorous testing and evaluation. Nonetheless, the delay in completing these tasks has not adversely affected the overall project timeline, as they were scheduled towards the end of the project and they will be concluded in the near future.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

With the development of two defect inspection tools in 3D for raw transparent and non-transparent GaN and 4H-SiC crystals, this project has directly addressed societal challenges with the potential to make positive impacts on various industries and the environment:
- Advance of the fundamental understanding of defect formation in Gallium Nitride and Silicon Carbide, which can lead to fine-tuning of reactors to produce GaN and 4H-SiC with higher yields.
- Accurate localization of defects in each produced ingot, thereby avoiding the processing of defective materials.
- Reduction of the price of GaN and 4H-SiC wafers, with positive impacts on the solid-state lighting and power electronics industries. Establishing a quality standard in the GaN and 4H-SiC crystal growth industry can result in more reliable, cost-effective, and high-performing Optoelectronic and Power electronic devices, enabling the full potential of these materials.
- Growth of less defective crystals can also contribute to a decrease in CO2 emissions, and a decrease of the energy consumption of reactors.
The successful completion of this project and its outcomes will promote more sustainable crystal growth and processing approaches among the scientific and industrial communities and reduced environmental impact while producing more reliable devices, and increasing the awareness about sustainable practices in the field of crystal growth and related industries.
At Scientific Visual, we place a growing emphasis on the potential impact of our technology in this field.

Besides, this project contributed to:
- Enhance career prospects after the fellowship, as the researcher in charge was recruited as a core team member by Scientific Visual.
- Exploit and disseminate the results and it fostered a close exchange of ideas with stakeholders from the GaN and SiC industries, who were identified as prospective clients.
- Communicate about the project activities to different target audiences by active participation in dissemination events, conferences, and trade shows. It successfully generated awareness about the benefits of early quality control inspection tools not only among the scientific community and prospective clients, but also among young researchers and students.
The support by Marie-Curie's research fellowship of this research project has been highlighted as a proof of its excellence at the communication and dissemination events.

Wafering map of a defective 4” SiC ingot with smart wafering optimization

4-inch SiC puck (left) and its 3D digital twin (right)