Optimisation of masked ion irradiation damage profiles in YBCO thin films by Monte Carlo simulation

Abstract

Systematic Monte Carlo simulation studies have been carried out to search for a possible optimal experimental condition on the irradiation damage profile production with a given mask structure. The results suggest that minimum ion scattering broadening tails could be achieved with projectile ranges in Nb mask about half of the mask thickness. Provided the projectile range to mask thickness is maintained, similar irradiation damage profiles could be created by different ions, including ions as heavy as Cu þ .

Study and optimization of ion-irradiated high Tc Josephson junctions by Monte Carlo simulations

“…The defect's depth distribution in bulk materials and single films is well known 17,18 , but little work has been done to study the LDD and its influence in the physical transport properties of irradiated JJ [19][20][21][22] . Recent developments in electron beam lithography to fabricate JJ at nanoscale require more accurate studies; we have used a numerical approach and Monte…”

High quality YBa/sub 2/Cu/sub 3/O/sub 7-δ Josephson junctions and junction arrays fabricated by masked proton beam irradiation damage

“…The simulation details have been described elsewhere [10]- [13]. The model mask structure is composed of an amorphous LaAlO substrate, 100 nm single crystalline YBCO, various LaAlO buffer layers and Au mask.…”

“…Firstly, the unsatisfactory performance is related to the difficulty in confining the damage profile due to mask side-wall scattering [10]. Such an unwanted damage profile broadening effect could be reduced by optimising the ion beam irradiation condition [11]- [13]. Secondly, mass disparity between negative electron and positive ion implies significant differences in irradiation defect production on different sublattice sites of YBa Cu O (YBCO) by electron and ion irradiations.…”