ALKALI-FREE BOROSILICATE GLASSES WITH LOW POST-HF ETCH ROUGHNESS

摘要

An article comprises a glass substrate. The glass substrate has a first surface having a plurality of vias therein, and a second surface parallel to the first surface. At least one of the first surface and the second surface is an etched surface having a surface roughness (Ra) of 0.75 nm or less. The glass substrate comprises, in mol percent on an oxide basis: 65 mol %≤SiO₂≤75 mol %; 7 mol %≤Al₂O₃≤15 mol %; 26.25 mol %≤RO+Al₂O₃−B₂O₃; 0 mol %≤R₂O≤2 mol %. RO=MgO+CaO+SrO+BaO+ZnO. R₂O=Li₂O+Na₂O+K₂O+Rb₂O+Cs₂O.