Method for determining material parameters of a doped semiconductor substrate by measuring photoluminescent radiation

摘要

Method for determining material parameters of a doped semiconductor substrate, including: applying electromagnetic excitation radiation in order to produce luminescent radiation in the semiconductor substrate, the temporal profile of the excitation radiation intensity is periodically modulated, so that the rate of generation of charge carrier pairs in the substrate has a maximum and minimum during an excitation period, and at least the relative temporal profile of the rate of generation G(t) is determined by time-dependent measurement of the excitation radiation intensity, time-resolved measuring luminescent radiation intensity emanating from a measuring region, at least the relative temporal profile of the intensity of the luminescent radiation Φ(t) is measured during an excitation period, determining a material parameter of the semiconductor substrate based on G(t) and Φ(t). The effective lifetime of the substrate is determined from the time difference between the maximum of G(t) and a corresponding maximum of Φ(t).

主权项

1. A method for determining material parameters of a doped semiconductor substrate by measuring photoluminescent radiation comprising the following processing steps:
A impinging the semiconductor substrate with an electromagnetic excitation radiation to generate luminescent radiation in the semiconductor substrate, with a temporal progression of an intensity of the excitation radiation being periodically modulated such that a generation rate G of charge carrier pairs, due to the excitation radiation, shows a maximum and a minimum during an excitation period in the semiconductor substrate (4), and with at least a relative temporal progression of the generation rate G(t) being determined via a time-dependent measurement of the intensity of the excitation radiation, B time-resolved measuring the intensity of the luminescent radiation emitted from a measuring area of the semiconductor substrate, with at least a relative temporal progression of an intensity of the luminescent radiation Φ(t) being measured at least during an excitation period, C determining at least one material parameter of the semiconductor substrate dependent on the temporal progression of the generation rate G(t) and the temporal progression of the intensity of the luminescent radiation Φ(t),in step C an effective life time τ of the semiconductor substrate is determined at least for an excessive charge carrier density Δnmax reached during one excitation period, by determining a temporal difference between a maximum of G(t) and a maximum of Φ(t) corresponding thereto.