Ultrafast semiinsulating InP:Fe-InGaAs:Fe-InP:Fe MSM photodetectors: modeling and performance

The response of InGaAs metal-semiconductor-metal (MSM) detectors as a function of all relevant detector parameters is investigated experimentally and theoretically. The calculations of the intrinsic detector response are carried out by taking fully into account the two-dimensional character of the problem. The generalized Ramo theorem is applied to obtain the induced current, which is the only measurable quantity. The calculations clearly demonstrate the distinct contributions of electrons and holes to the response. The extrinsic response is derived taking parasitics, which are obtained in different ways, into account. A full-wave analysis of the detector circuit, solving Maxwell equations, is performed. The resulting S₁₁ scattering parameter is measured by means of a network analyzer. Fitting of the calculated and measured S₁₁ parameters to an equivalent circuit diagram yields the values of the parasitic elements. Perfect agreement between calculated and measured data is found