Säteilyhärteniä

Säteilyhärteniä, known in English as radiation hardening, is a design technique used to protect electronic components from damage or malfunction caused by ionizing radiation. This is particularly important for devices operating in environments with high levels of radiation, such as outer space, nuclear reactors, or medical imaging equipment.

The primary goal of radiation hardening is to ensure the reliability and longevity of electronic systems when exposed to energetic particles and electromagnetic waves. Radiation can cause several types of damage. Total Ionizing Dose (TID) effects accumulate over time, leading to gradual degradation of performance, such as shifts in transistor threshold voltages or increased leakage currents. Single Event Effects (SEEs) are transient or permanent changes caused by a single energetic particle striking a sensitive region of a semiconductor device. These can manifest as bit flips in memory (Single Event Upsets or SEUs), temporary circuit disruptions (Single Event Transients or SETs), or even permanent damage like latch-up or burnout.

Various methods are employed to achieve radiation hardening. Material selection is crucial, with some materials being inherently more resistant to radiation than others. Device architecture and fabrication processes can be modified to reduce susceptibility. For example, thicker gate oxides or different semiconductor materials like Silicon-on-Insulator (SOI) can improve resistance. Redundancy, where multiple components perform the same function and their outputs are compared, is another strategy to mitigate the impact of SEEs. Shielding, using materials to absorb or deflect radiation, is also a common approach, though it adds weight and volume. Finally, error detection and correction codes are used in digital systems to identify and fix data corrupted by radiation. The specific techniques chosen depend on the expected radiation environment, the criticality of the application, and cost considerations.