Angle-resolved light scattering (ARLS) is used to estimate the root-mean-square (rms) slopes of rough surfaces having a well-defined lay, and the effect on slope measurements caused by changing the angles of incidence and scattering is investigated. The ARLS patterns are taken with the Detector Array for Laser Light Angular Scattering (Dallas) research instrument, and the rms slopes are obtained from the angular widths of these patterns. In general, it was found that the angular width, and thus the estimated rms slope, is surprisingly insensitive to relatively large changes in both the incident and scattering angles of light. These results are independent of surface material and are valid for both sinusoidal and random rough surfaces with lay. The principles, experiments, analyses, and conclusions involved in using ARLS to estimate rms surface slopes are described.

The reflection of a monochromatic plane wave falling obliquely upon the surface of an arbitrary, flat, depth-dependent material is investigated theoretically. The complex reflection coefficient for either principal (s or p) polarization of the field is shown to satisfy a non-linear differential equation of the Ricatti type. An alternate formulation based on the wave immittance (i.e., jmpedance or a dmittance) functions is also presented. The immittance functions are shown to satisfy Ricatti differential equations of their own. The reflection coefficient formulation and the wave immittance formulations are related via a bilinear algebraic transformation. Singularities appearing in the reflection coefficient formulation may be suppressed in the immittance formulation, and viceversa. The advantage of either formulation is that the reflection coefficients for an arbitrary, depth-dependent medium can be obtained directly without having to solve Maxwell's equations for the internal field configurations.

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The effects of 60Co γ-ray and high-energy neutron displacement damage on impurity conduction in epitaxial gallium arsenide were investigated. The activation energy (ε2) associated with the transition regime of the impurity conduction process was found to increase by a factor of 5 as a result of 60Co γ irradiation, and only by a factor of 1.6 for a comparable neutron irradiation. In addition, the ratio of the Hall carrier density at low and high temperatures, (nH)4 K/(nH)300 K, decreased by a larger amount for 60Co γ irradiation than for neutron irradiation. The effects of neutron irradiation are explained in terms of increased compensation. For the case of 60Co γ irradiation, it is postulated that a new donor level is introduced which does not participate in the impurity conduction process. In addition, with respect to the impurity conduction process, it is found that ε2 is proportional to ε1 (the conduction-band activation energy) and varies inversely with neutral donor spacing in accord with the model proposed by Mikoshiba. Also ρ30, the hopping regime resistivity, is found to vary inversely with the square of the free-carrier concentration and exponentially with the quantity 0.6/ND1/3a.

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