Glass wafer and method for producing same

A process for producing a glass wafer comprising a glass substrate comprising at least one opening, having two mutually opposite lateral faces and one circumferential edge face, comprising:

• providing the glass substrate in pane form;
• directing a laser beam from an ultrashort pulse laser onto one of the lateral faces of the glass substrate in pane form, wherein the laser beam is formed by focusing optics to an elongated focus in the glass substrate in pane form such that incident energy of the laser beam creates filamentary damage in a volume of the glass substrate in pane form, a longitudinal direction of which is at right angles to at least one of the lateral faces of the glass substrate in pane form, and wherein the filamentary damage by the ultrashort pulse laser is created by incidence of a pulse or pulse packet having at least two successive laser pulses;
• and
• etching the glass substrate in pane form at least in a region in which filamentary damage has formed in the glass substrate in pane form in a liquid etch medium, wherein the filamentary damage is widened to channels, wherein the liquid etch medium is or comprises an alkali.