Radiation resistant MOS devices

A detailed study indicates that the radiation resistance of MOS transistors is controlled by the details of the technology. It has been found that an MOS structure can be created that remains operational for gamma radiation doses of greater than 10⁷Rad. It will be shown how the radiation resistance varies with gate oxidation and the particular metals employed. The interrelation between radiation and thermal stability will also be discussed. It will be shown that there is some connection between the two as long as the same basic technology is used. It is possible, however, that combinations which result in thermal stability can still show a low radiation resistance.