X‐ray Reflectivity from Sinusoidal Surface Relief Gratings

The sinusoidal shape of light‐induced surface relief gratings of polymers can be probed by x‐ray scattering techniques. A particular approach of kinematic x‐ray scattering theory is developed to interpret experimental scattering curves. The simulations demonstrate the particular sensitivity of x‐ray reflectivity for very small grating amplitudes. At angles of incidence close to the critical angle of total external reflection a grating amplitude h < 2 nm already provides measurable grating peaks. In general the grating amplitude h can be measured from the envelope function over the grating peak maxima. The capability of the approach is demonstrated by simulation of the reflection curve recorded from a polymer sample with non uniform grating height.