Performance evaluation of an Active Pixel Sensor Test Structure for space science applications

An Active Pixel Sensor Test Structure, commissioned by the Rutherford Appleton Laboratory CCD Technology Group and designed by the Microelectronics Design Group, is being tested and evaluated by the University of Birmingham. The Test Structure includes four 16×16 pixel arrays, each array featuring a different 25 μm pixel design: Photogate, QuadruDot, n-type diffusion [Diode(ndps)] and p-type diffusion [Diode(pdNw)] photodiodes. Measurements are currently underway to characterize the Active Pixel Sensor performance. Initial measurements indicate pixel array gains of 2.9, 3.4, 38 and 50 electrons per ADC unit, for the QuadruDot, Photogate, Diode(ndps) and Diode(pdNw) arrays. The test-structure architecture, experimental set-up, results and conclusions are discussed, with reference to the performance benefits of this technology for future space applications.