![A schematic image of a thin film transistor consisting of carbon nanotubes (CNTs) on an SOI ("silicon on insulator") as shown in the scanning electron microscope inset image. Technologies like CNTs form the basis of the "beyond-silicon" electronics, which are poised to take electronics into the future, beyond the ultimate capabilities of silicon. A schematic image of a thin film transistor consisting of carbon nanotubes on an SOI ("silicon on insulator") as shown in the SEM inset image.](https://webarchive.library.unt.edu/web/20161128073844im_/http://www.nrl.navy.mil/estd/sites/www.nrl.navy.mil.estd/files/styles/400width/public/images/radiationeffects.png?itok=UcDcQ453)
In electronics research, the typoes of radiation of primary importance are particle irradiation in the form of electrons, protons, neutrons, and heavy ions; and irradiation by photons in the form of gamma rays and x-rays. The effects of radiation are total ionizing dose (TID), which causes charge buildup at interfaces, single event effect (SEE), which causes changes in logic state of transistors, and displacement damage, which causes permanent damage of the crystal lattice.
In the early 1960s, ESTD researchers first identified the sensitivity of CMOS transistors to TID, and have been on the forefront of radiation effects research since then. With the proliferation of digital logic, SEE has become a dominant concern, and ESTD scientists have created a world-class laser facility to simulate the impact of ion strikes, enabling nondestructive, precise analysis of complex circuits. Displacement damage affects a variety of electronics parts, and in particular optoelectronic technologies, especially solar cells. ESTD has established an internationally accepted methodology for analyzing displacement damage dose effects in materials and devices.
Operation in a radiation environment is almost exclusively a requirement of commercial and military space systems, so makers of standard commercial electronic parts seldom address radiation effects. For military systems to fully capitalize on the capabilities of cutting0edge electronics, the mechanisms of radiation effects must be analyzed and understood in the rapidly evolving world of commercial electronics. The future of radiation effects research lies in continually studying emerging and next-generation silicon technologies while developing new technologies that will ultimately take us beyond the limitations of silicon.