Glass wafer and glass element for pressure sensors

A glass wafer comprising:

• a sheetlike glass substrate 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;
• and
• an opening defined in the glass substrate through a thickness of 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 along the thickness that has a minimum length of at least 10 um and a side face with a surface characterized by a skewness (Ssk) that is in the range of −5.0 to −0.001 or 0.001 to 5.0, the skewness (Ssk) being defined by:
• Ssk
• =
• 1
• S
• q
• 3
• [
• 1
• A
• ⁢
• ∫
• ∫
• A
• (
• Z
• ⁡
• (
• x
• ,
• y
• )
• 3
• )
• ⁢
• dxdy
• ]
• wherein Sq denotes a mean square roughness in millimeters squared (mm2) of the surface, A is an area in millimeters squared (mm2) of an integration zone of which the skewness is determined, Z(x,y) is a height value in millimeters (mm) of the surface at coordinates x, y, the height value being expressed relative to an arithmetic mean of height values of the surface, and Z(x,y) is positive if a point on the surface is higher than a mean, and negative if the point is below the mean.