Abstract

When CMOS Image Sensors appeared around the mid ‘90s, they promised many advantages with respect to the then dominant solid-state imaging device, the charge-couple device (CCD). The CCD , invented in 1969, was threatened to be sent into a slow but inexorable retirement. CMOS image sensors have clear advantages in terms of speed, ease of use, functionality integration, radiation hardness, power consumption and more. CMOS being the technology underpinning the microelectronics revolution, which has brought into our daily life high performance computers and complex mobile devices, just to mention some, it became possible to have a whole camera on a single piece of silicon. Supported by a world-wide industry effort to improve the technology, CMOS sensors have now overtaken CCDs as the main imaging devices. Almost every digital camera has today a CMOS sensor at its heart, even for professional devices. Scientific CMOS is now also there, with noise performance comparable to CCDs. CMOS Image Sensor are going strong, but about 20 years from their invention, is it time for a new imaging revolution? At the Rutherford Appleton Laboratory, the largest UK national laboratory, managed by the Science and technology Facilities Council (STFC), we have been developing CMOS image sensors almost since the ‘90s. Initially driven by the requirements of the laboratory scientific applications, like space science and particle physics, this activity has then spun off into multiple areas, both in science and in industry. To enable this, we have been expanding the reach of these technologies, moving it beyond the realm of visible light into different wavelength, like UV or X-rays, as well as charged particles. We invented and designed the first direct electron detection CMOS image sensor, which changed the imaging technology for transmission electron microscopy. We made sensors covering a very large area or with a very high dynamic range. Backside illumination for high sensitivity UV and low energy X-rays is being developed. And last but not least, we develop a new technology that enables imaging at millions of frames per second and that could make CMOS and CCD , individually taken, look like dinosaurs.