Amorphous silicon vertical pixel development for high-energy particle detectors: Modelling and technology

The properties of hydrogenated amorphous silicon (a-Si:H) have proven to be suitable for the fabrication of large-area, high-energy particle detectors. A compact, vertically integrated pixel design thus consists of the sensor material, the bias resistor and the coupling capacitor. Preliminary fabrication results are presented for each of these elements. We use a two-dimensional model of the sensor to study the current crosstalk for a given pixel topology on the wafer. Vertically integrated capacitors with a breakdown electrical field greater than 4.5 MV/cm are measured and their stability is demonstrated. Promising results for vertical resistors are also presented. Overall, this paper presents our progress in the development of this technology system for pixel fabrication.