A method of etching a semiconductor body.

摘要

A method of etching a semiconductor body having first (6) and second opposed surfaces and having a first semiconductor region (1) adjacent the first surface (6) and a second semiconductor region (2) disposed between the first semiconductor region and the second surface, the first (1) and second (2) semiconductor regions being formed such that the second semiconductor region (2) first absorbs radiation at a wavelength less than the wavelength at which the first semiconductor region first absorbs radiation. The second surface provides an optically distinguishable feature, for example an optically opaque conductive layer (3) formed with an aperture (4). The method further comprises aligning a radiation source with the feature (4) and activating the radiation source to produce radiation having a wavelength or range of wavelengths shorter than or equal to that at which the first semiconductor region (1) first absorbs radiation but longer than that at which the second semiconductor region (2) first absorbs radiation so that the radiation induces etching of the first semiconductor region in alignment with the optically distinguishable feature of the second surface but does not induce etching of the second region (2) so enabling a hole (8) to be formed aligned with the aperture (4) to allow light to pass through the second region (2) which may comprise a transmission etalon in the form of a multiple quantum well structure.