A substrate comprises glass, sapphire, silicon and/or aluminosilicate, and has at least one recess or through-opening. The at least one recess or through-opening is formed by anisotropic removal of substrate material by etching a portion of the substrate that has been modified by a pulse of laser radiation in a direction of a thickness of the substrate. The modified portion of the substrate extends along a beam axis of the laser radiation. The pulse of laser radiation was applied with a focus extending from a first focal depth positioned past one side of the substrate to a second focal depth located at an opposite side of the substrate.