Low temperature wafer-to-wafer bonding

The bonding interface between the specific semiconductor absorber and the CMOS readout is made with the modified EVG®580 ComBond® system. The system was modified by G-ray to obtain a low-energy Argon plasma chamber that enables to clean the wafer surface at the atomic scale, without damaging the crystalline structure, before the bonding process takes place. Additional modifications of the system are explored to optimize both the bonding strength and the electrical charge collection across the bonded interface and reduce costs while improving quality.

Modified ComBond System at G-ray

Large-area detector production

G-ray’s unique manufacturing processes based on bonding technology enable the production of large-areas detectors, in the range of 100 cm2 or even more, per detector with a pixel pitch in the range of 25-50 µm. This is to be compared with standard current bump-bonded solutions where surfaces are typically in the 2 cm2 range with a pixel pitch ranging within 75-150 µm for industrial applications. Large-area detectors for industrial X-ray demands the tiling of detector modules to obtain the desired detector surface: of course, the larger the initial detector area, the less tiling required allowing for lower-costs and reduced complexity.