Generation of optical contrast in insulating materials by irradiation withfocused ion beams

The optical properties of crystalline insulating materials can markedly be modified by irradiation with energetic ions. The exposed areas of such mate rials absorb and reflect light more strongly than non-irradiated ones. In t his way, optical contrast is created. With modern equipment, ion beams of s ufficient intensity can be focused to submicron dimensions. Thus, both anal og and digital information can be recorded with pixel densities of Gbit/cm( 2) to Tbit/cm(2). In particular, crystalline films elf group-IV elements of the periodic system, such as Si, SIC and Co (diamond), are best suited for this novel ionographic process. The physical foundations of this technolog y and the resulting properties of the recorded data will be discussed.