There is no environment that is more extreme or harsher than space. Yet humans are continually expanding their presence to this dangerous place in the form of satellites, space missions and probes.
As the world continues to push the boundaries of space and other harsh environments, the importance of radiation hardened (rad-hard) electronic components grows. These devices allow systems in the harshest of conditions — space, nuclear facilities and military systems — to continue to function properly despite exposure that would damage or destroy conventional processors.
These rad-hard components must be able to operate in spacecraft electronics and other applications that are exposed to extreme temperatures ranging from -55° C to 125° C during missions that can last more than 15 years. The chart below shows some of the other benefits to rad-hard electronic components.
Types of rad-hard components
Rad-hard devices are expensive to produce due to the raw materials used and special shielded packaging on the electronic parts to keep radiation at bay. There are other ways of dealing with space radiation like redundant subsystems, selective shielding and upscreening commercial off-the-shelf electronics for reliability.
However, these rad-hard electronic components are designed to provide capabilities such as on-board processing and cybersecurity and often replace multiple previous generation devices in a smaller physical footprint.
These types of devices include
- Single board computers for satellites.
- Standard components — used in space and missile defense.
- Memory ICs — like SRAM, C-RAM and PROM.
- FPGAs — that can be used as a drop-in replacement in legacy systems.
- ASICs — application specific devices used in space landers, rovers and satellites.
According to market research firm Grand View Research, the rad-hard electronics market is expected to grow at a compound annual growth rate (CAGR) of 5.7% from 2024 through 2030. This will be due to global demand for SATCOM in electronic gadgets, dependable and safe electronics and other future use cases.
Difficult manufacture
One type of technology used to create rad-hard semiconductors is silicon-on-insulator (SOI). SOI’s active circuitry is separated from the bulk silicon substrate by a thin layer of oxide insulation. This reduces parasitic circuit capacitances as well as reduces the likelihood of singe event upsets triggering failures.
Another approach is to use additional implant stages on conventional bulk-silicon processors that make existing processors and other semiconductors more resilient to radiation damage. This uses a guard ring in the substrate beneath the transistor areas, preventing parasitic transistors forming that would otherwise cause latch-up.
These processors make rad-resistant chips more difficult to manufacture and design compared to traditional silicon ICs. Standard chipmaking methods cannot be used to make chips that survive ionizing radiation, special techniques must be used. This, obviously, costs more than traditional semiconductor manufacturing, according to research from Sandia National Laboratories.
Sandia and other organizations are working to develop new techniques that will lower the cost to develop these semiconductors through patterning, oxide deposition, ion implantation and more.
Space systems
The largest use case for rad-hard devices is in space. It is the final frontier and not surprisingly the harshest environment known to mankind. These MPUs are essential for:
- Crewed space missions
- Satellites for GPS communications
- Satellites for weather monitoring
- Satellites for planet monitoring
- Space probes
- Space telescopes
The MPUs and other components must withstand not just the vacuum of space but withstand various other conditions that are impacted while on Earth such as cosmic rays, solar flares and no possibility of repairs.
Other use cases
There are primarily three other use cases for ruggedized radiation-hardened electronics. These are:
- Nuclear power plants
- Military systems
- Medical imaging equipment
Rad-hard processors in nuclear reactors can withstand radiation leaks and ensure fail-safe operations, while rad-hard devices in the military are used for missiles, radars and secure communications where radiation exposure is typically higher. In medical equipment like X-rays and CT scanners, rad-hard devices allow for reliability for long periods of time in ionizing radiation environments.