Anisotropic electrical conduction on ion induced nanorippled CoSi surface

Abstract

We investigate electrical conduction on ion-induced nanorippled Co0.69Si0.31 surfaces. Oblique Ar+ ion bombardment performed by varying the ion fluence within 1.12 × 10 18- 6.73 × 10 18 ions cm- 2 showed well-ordered ripples aligned perpendicular to the ion beam direction. At higher fluence, hillock like structures evolve due to shadowing effect. Electrical measurements on the pristine and patterned surfaces show strong dependency on the patterning of the surface. Channel resistance is found to be highly dependent on ripple amplitude, and therefore, an anisotropy in electrical response along two orthogonal directions of the sample surface is evident due to the difference in effective channel length as a consequence of ripple formation. The surface resistance is found to be dependent on the ripple amplitude of the patterned surface. The present ion irradiation based post processing of the grown films present a unique approach towards a systematic improvement in electrical conduction.