IMEC builds reliable 11 megapixel micro-mirror array for high-end industrial applications

Each mirror in the array is 8µm x 8µm and can be individually tilted by the high-speed integrated CMOS circuitry underneath the array. This device fits in IMEC’s CMORE initiative, which offers cost-effective solutions for continued system scaling, not by shrinking CMOS but by focusing on monolithic co-integration of heterogeneous technology.

IMEC’s 10cm² 11 megapixel mirror array has a pixel density that is almost double that of comparable state-of-the-art micro-mirrors. And IMEC has demonstrated that its mirrors show no creep and meet a 1012 cycles mechanical lifetime. Integrated micro-mirror arrays such as this one, are used in, for example, video projection or lithography mask writers.

IMEC fabricated the 8µm mirrors on top of foundry high-voltage 0.18µm CMOS 200mm wafers with 6 interconnect levels. The array was built using IMEC’s proprietary SiGe-based MEMS platform, meeting the mirror’s mechanical reliability requirements, device flatness, and compatibility with high-speed CMOS. Poly-SiGe was chosen as structural material for the mirrors, instead of Al. Poly-SiGe solves many of the reliability issues of Al-based mirrors, and it is compatible with above CMOS processing, allowing a smooth integration with the CMOS chip below.

IMEC’s CMORE initiative offers cost-effective solutions for monolithic co-integration of heterogeneous technologies. The services offered range from development-on-demand, over prototyping, to low-volume production. These services profit from the expertise in many research areas available at IMEC. The CMORE solutions are implemented in IMEC’s 200mm fab with advanced packaging capabilities, such as 3D integration. The two process platforms involved are a 0.13µm CMOS process and a versatile SiGe above-IC MEMS process. On customer demand, the CMORE solution can be migrated to IMEC’s 300mm fab.