Considerations for Hardening MOS Devices and Circuits for Low Radiation Doses

The radiation response of MOS devices has been shown to be dependent on the details of the device processing and of the device design. To produce megaradhard devices process controls have been used and special design considerations have been developed. This paper considers the special problem of hardening IC's for low radiation doses (1-10krad). A worst case calculation of the radiation induced threshold voltage shift shows that it may be possible to guarantee the total dose hardness of MOS IC's for low doses by controlling only the gate oxide and field oxide thickness with no other process controls.