Influence of topological constraints on ion damage resistance of amorphous hydrogenated silicon carbide

摘要: Abstract Radiation damage in materials is an important reliability issue applications ranging from microelectronic devices to nuclear reactors. However, the influence of atomic structure and specifically topological constraints on ion resistance amorphous dielectrics has until recently been largely neglected. We have investigated 120 keV He + for a series hydrogenated silicon carbide (a-SiC:H) thin films. Changes elemental composition induced by irradiation were monitored using reaction analysis, Rutherford backscattering spectroscopy, transmission Fourier-transform infrared electron microscopy while changes mechanical properties nanoindentation measurements. show that doses producing up one displacement per atom, significant hydrogen loss, bond rearrangement, film shrinkage, stiffening films with mean coordination (〈 r 〉) ≤ 2.7, comparatively minor observed 〈 〉 > 2.7. The radiation hardness threshold at 〉 rad > 2.7 above theoretically predicted rigidity percolation c  = 2.4. Based elimination terminal C H bonds Si CH 2 linkages, higher interpreted as evidence these are too weak function high-energy collisions. Eliminating increased 2.7, agreement  = 2.7. These results demonstrate key role provide additional criteria design ion-damage-resistant materials.