Application of wet chemical selective etch techniques to the fabrication of thin silicon detectors

Abstract

Anisotropic selective etching of silicon was applied to the fabrication of dE/ dx-detectors with a thickness between 20 and 40 μm using 〈100〉-oriented FZ-silicon wafers and KOH/H 2O-solution as an etchand. Main etch parameters have been investigated to demonstrate the advantage of anisotropic selective etching in comparison with the isotropic etch process. As an example the properties of 400 mm 2 ion-implanted and oxide passivated dE/ dx-detectors with anisotropically etched membranes are described. Finally, the fabrication possibilities of detectors with thicknesses up to 1 μm with high thickness accuracy across the detector area are discussed.