Abstract The mechanical collimator, used in combination with an Anger camera in nuclear-medical imaging studies, can be replaced with a radiation detector, which performs the function of electronic collimation. The two-detector system is based on the Compton scattering of incident gamma-photons. Although germanium is more efficient in the absorption of gamma-photons by the Compton process than silicon, silicon has advantages which cannot be overlooked when choosing a substrate material on which to fabricate the radiation detector to be used in the electronic collimator system. The semiconductor drift chamber (SDC) principle offers advantages in the construction of a two-dimensional radiation detector array. Simulations of the potential field within the detector array will be shown, as well as the design and processing sequence used in the fabrication of a 3 × 3 SDC array.