Glass-ceramics with plasma resistance and parts for dry etching comprising the same

A crystallized glass comprising a crystalline structure and a vitreous structure,

• wherein the crystallized glass contains 40% to 80% by weight of the crystalline structure,
• wherein the crystalline structure comprises lithium disilicate as a main crystalline phase and at least one crystalline phase of lithium phosphate (Li3PO4), lithium metasilicate (Li2SiO3), silica (SiO2), or zirconia (ZrO2) as a sub-crystalline phase,
• wherein the crystalline structure contains 60% to 95% by weight of the lithium disilicate as the main crystalline phase,
• wherein the crystallized glass has a surface roughness of 0.01 μm to 0.1 μm,
• wherein the main and sub-crystalline phases have an average grain size of 0.05 μm to 0.5 μm after performing a primary crystallization heat treatment at a temperature in the range of 400° C. to 850° C.,
• wherein the main and sub-crystalline phases have an average grain size of 0.5 μm to 5 μm after performing a secondary crystallization heat treatment at a temperature in the range of 800° C. to 950° C. after the primary crystallization heat treatment, and
• wherein the crystallized glass has plasma corrosion resistance required for dry etching process.