Patent ID: 7362108

Claim:
A method of measurement of sidewall damage in a sample under study, comprising the steps of: (a) positioning the tip of a near-field microwave probe (NMP) a predetermined tip-sample separation distance over the surface of said sample under study, said sample under study including a plurality of trenches etched in a low-k film, said trenches having sidewalls; (b) measuring the dielectric constant k meas of said sample under study by said NMP; (c) determining geometries of said sample under study; (d) calculating a capacitance C meas of said sample under study based on said dielectric constant k meas and said geometries of said sample under study; (e) modeling a total capacitance C model of said sample under study in accordance with a predetermined modeling algorithm; (f) finding a dielectric constant k eff at which said C model substantially equals said C meas , wherein said k eff is the effective dielectric constant of said sample under study; and (g) extracting a measure of the sidewall damage using said k eff Δ ⁢ ⁢ k · t d = ( S 2 ) ⁢ ( k eff - k ) , wherein Δk·t d is the measure of sidewall damage, t d is the thickness of the sidewall damage; Δk is the change of the dielectric constant due to the sidewall damage, k is the dielectric constant of the undamaged said low-k film, k eff is the effective dielectric constant of the low-k material remaining between the trenches after etch, and S is the spacing between trenches etched in said low-k film.