Radiation hardened chips are less focused on the physical shielding of the chip with iron/lead/steel/etc (though they do have shunts that minimize ESD damage typical in high RAD environments), but primarily on 2 areas:
Error detection and recovery - similar to
, but instead of guaranteeing data integrity, the radiation hardened chips assures computational integrity. This is done through methods such as having parallel circuits in the chip that both run the same instruction and checking if the outputs match or logic that runs the instructions multiple times and comparing the results. If the results are different(signaling radiation interference), then the chip itself reconciles the differences so the software doesn't crash or get invalid results.
Gate design differences - logic gates are typically larger or work at higher PN junction thresholds or use different doping agents to make them physically less susceptible to having a computational error when struck with a high energy particle.
