Space-hardened microelectronics bring new advances

A minimum total dose radiation hardness of 10,000 Rads is required for space-deployed VLSI/VHSIC electronics, for typical orbits and a five-year mission length. Silicon-on-sapphire (SOS) IC technology can be used to fabricate semiconductor devices which are hardened to cosmic radiation effects. Although more research is needed to establish the details of neutron and ionizing radiation effects on Schottky barrier heights and noise figures, available data indicates that GaAs field effect transistors may be as hard as, or harder than, comparable silicon devices. Assuming a minimum feature size of 0.5 microns, a 1985-1990 period list of engineering requirement expectations is presented which envisages only specialty applications for SOS and GaAs systems. Attention is given to the longer term requirements of spacecraft planned through 1995, which may routinely undertake 5-10 year missions rather than the 3-year average of present ones.