Influence of self-affine and mound roughness on the surface impedance and skin depth of conductive materials

Abstract

In this work, we explore the influence of self-affine and mound surface roughness on the surface impedance and skin depth. For self-affine roughness, the surface impedance and skin depth increases with decreasing the roughness exponent H (for k F j q 1 with k F the Fermi wavevector), and/or increasing roughness ratio w=j; where w is the rms roughness amplitude and j the in-plane roughness correlation length. For mound roughness, the surface impedance and skin depth decrease monotonically with increasing average mound separation l when l . z with z the correlation length (assuming k F z q 1), while for l , z they are both decreased with increasing l: q

A RF Redundant TSV Interconnection for High Resistance Si Interposer

“…Because surface roughness of the copper generates parasitic inductance, the surface impedance will change and results in conductor loss [ 30 ]. Especially when the skin depth corresponding to the operating frequency is less than or equal to the surface roughness, the effect of surface roughness will become very significant [ 31 , 32 ]. Additionally, the resistivity of the conductor also affects the conductor loss.…”