At the end of the project, the CITCOM system results in two modules ready to be applied within a MEMS manufacturing facility: A 3D vision in-line system to inspect 100% of production flanked by a side-line X-ray system, for selective and advanced analysis.
The optical module consists of a conventional micro-electrical wafer prober, which has been retrofitted by with a plenoptic camera. This technology resolves details at the micron scale in 3D, with high throughput, up to 80 fps. The chosen cameras are compact and have an extended depth of focus compared to microscope cameras with similar optical properties because the microlenses have various focal lengths. The combination of all these advantages renders this technology ideal for MEMS inspection (Figure 1).
The X-ray system mainly consists of X-ray source, detector and manipulator. Optimization of the system resulted in a maximal spatial resolution of 0.5 m, enabling detection of sub-micron defects. The manipulator, designed and developed specifically for CITCOM, can manoeuvre up to 8” wafers with three axis translations and one axes full rotation (Figure 2).
A dedicated software automates wafer handling and inspection on both systems. User interaction and direct control of the plenoptic system is provided through an industry-ready automation software, which has been extended to the CITCOM components and functionalities. A backend software guarantees integrated control of the imaging hardware, steers the image analysis workflow and relays information to all components. Automated analysis includes image reconstruction, stitching and noise filtering as well as metrology and automated defect recognition (ADR). The ADR applies Deep Learning to detect anomalies such as defects and foreign particles (Figure 3).
The system’s functionalities have been tested and successfully validated for reliability, robustness and performance on MEMS samples provided by end-user partners. The restrictions related to the COVID-19 pandemic, prevented to setup the systems in a real production environment. Thus, final validation has been conducted in a laboratory environment based on production-like samples and by applying production-like conditions and validation protocol, fully coordinated by the main end-user partner.
Reliability/ageing testing conducted on specialised laboratories on the samples provided by Microchip have shown that critical features which can be identified by the CITCOM technology, have a relevant impact on the MEMS life. By applying 100% in-line inspection and providing the tools to identify such defects at early production stage, the CITCOM system has the potential to significantly improve production efficiency and product yield and quality.
The economic benefit of the system was shown by benchmarking with state-of-art methods at Microchip Technology (i.e. human experts with high magnification microscopy). Life Cycle Assessment and Life Cycle Costing also showed a positive environmental impact. Finally, different recycling scenarios to be associated with the CITCOM technology have been proposed, to promote a circular economy approach.
The successful closure of the CITCOM project is underlined by the concrete intent shown by several partners to continue the collaboration beyond the end of the project. This phase will allow to test the setups in a real production environment and to finalise the technology toward commercialisation.
The project results have been promoted through participation to various workshops/conferences as part of dissemination and communication actions. An exploitation plan for the key results and developed technology has been prepared. Several partners involved into the project including a major end-user intend to bring the developed technology into a further finalisation and commercialisation phase, starting right after the end of the project.
