Patent ID: 8436996

Claim:
An apparatus for enhancing the electromagnetic signal of a sample for ellipsometry comprising: a) at least one substrate layer; b) at least one auxiliary layer bound to said at least one substrate layer, wherein said at least one auxiliary layer has a thickness and refractive index which produces deconstructive interference about s-polarization reducing the reflection of a component with s-polarization to a minimum, wherein said thickness and said refractive index of said at least one auxiliary layer are dictated by the equations d = λ A ⁡ ( n - 1 ) + B ⁡ ( n - 1 ) 2 ⁢ ⁢ and ⁢ ⁢ n op = .85 + 0.189 ⁢ ⁢ n s , where A=37.26(n s −1.682) −1/8 , B=14.587(n s −2.171) 1/6.5 , n≠1, d is said thickness of said auxiliary layer, λ is the wavelength of a light source, n is the refractive index of said auxiliary layer, n s the refractive index of said substrate layer, and n op is the optimal refractive index.