Transient and steady-state radiation response of CMOS/SOS devices

In an investigation to characterize the radiation properties of a pilot line product capability for manufacture of MNOS memory arrays, a CMOS test vehicle proposed as the building block for the array electronics was tested in a nuclear environment. The test device was a CD4007 configuration fabricated with an unhardened SiO2 gate insulator on a sapphire substrate. Test devices were made with aluminum and silicon gates, and test samples were selected to satisfy the requirement of operating satisfactorily with a source-drain voltage ≤21.5 volts. All tests were conducted with a drain-source voltage of 20 volts and gate biases in the range of 0 to 20 volts. The tests were as follows: (1) transient photo-current, (2) transient annealing, (3) total dose, (4) survivability, and (5) neutrons. Facilities at AFCRL were used for the first four and the Aberdeen Pulse Reactor for the last test. The tests were conducted in the order listed above on different batches of samples for each test.