A flexible scanning electron-beam system for annealing ion-implanted semiconductors or partially processed devices, direct device fabrication, or other high flux thermal processing is described. A maximum beam current of 3 mA in a 40 μm spot is available at accelerating voltages of up to 30 kV. Microprocessor controlled scanning over a 10 mm square field is available in this system. Resistor structures and diode arrays fabricated by e-beam annealing of ion-implanted layers show an edge resolution of 40 μm between unannealed and annealed regions. The diodes have characteristics close to those predicted for ideal structures and may be fabricated in arrays to make integrated devices such as vidicon targets.