Abstract: A glass wafer is provided that includes a sheetlike glass substrate with an opening. The sheetlike glass substrate is configured for use in a sensor selected from a group consisting of a pressure sensor, a piezoresistive sensor, a capacitive pressure sensor, and a piezoresistive pressure sensor. The opening is defined in the glass substrate from a first surface to a second, opposite surface. The opening has a cross-sectional area that is delimited by a straight portion having a minimum length of at least 10 ?m and a side face with a surface characterized by a skewness (Ssk) of at most 5.0.

Abstract: A spacer wafer for producing spacers of electro-optical converter housings is provided. The spacer wafer is a transparent glass plate having a multiplicity of openings separated from one another and distributed in a grid so that singulated spacers are obtainable by severing sections of the glass plate along separating lines between the openings. The openings have side walls with microstructuring that has a roughness with an average roughness value Ra of less than 0.5 ?m with a measurement distance of 500 ?m.