Radiation effects and radiation hardness solutions for single-walled carbon nanotube-based thin film transistors and logic devices

We have systematically studied the radiation effects on both p-type and n-type single-walled carbon nanotube (SWCNT) thin film transistors (TFTs) using aligned CNT arrays and semiconducting CNT networks as conductive channels. The main electrical parameters were extracted and studied statistically to help determine both the radiation effects and the underlying physical mechanisms. We found that the predominant factors affecting the total ionizing dose (TID) effects in SWCNT-based TFTs are the carrier doping effect of the air molecules for p-type TFTs, the electron doping effect of the fixed charges for n-type TFTs, and the junction contact improvement for CNT-network TFTs. As a result, specific methods were proposed to act as guidelines to eradicate the corresponding causes and improve the radiation hardness performance of SWCNT-TFTs, e.g. by optimizing the shield or insulator materials, preliminary radiation treatments and raw CNT materials selection for future application of SWCNT-based complementary metal-oxide-semiconductor (CMOS) devices. In contrast, we can also use the radiation method to control the threshold voltages of the SWCNT-TFTs quantitatively according to our experiments. Additionally, we designed and fabricated radiation-stable ambipolar SWCNT-TFTs for assembly of CMOS-like logic inverters, which showed high-radiation hardness performances up to a TID of 5000 krad (Si).