High purity cordierite material for semiconductor applications
Disclosed is a cordierite sintered body comprising from 90 to 98% by volume of a cordierite crystal phase as measured using x ray diffraction, SEM and image processing methods wherein the cordierite sintered body has at least one surface comprising pores having a diameter of from 0.1 to 5 um as measured using SEM and image processing methods. The cordierite sintered body has a Young's modulus of about 125 GPa or greater, and volumetric porosity of less than about 4%. Methods of making the cordierite sintered body are also disclosed.
1 . A cordierite sintered body comprising: wherein the cordierite sintered body has at least one surface comprising pores having a diameter of from 0.1 to 5 um as measured using SEM and image processing methods, wherein the cordierite sintered body comprises a cordierite crystal phase in an amount by volume of from about 95% to about 98% and a sapphirine crystal phase in an amount of from about 2% to about 5% measured using x ray diffraction, SEM and image processing methods, and the cordierite sintered body having a Young's modulus of from 125 to 140 GPa, as measured in accordance with ASTM E1876-15.
2 . The cordierite sintered body of claim 1 , wherein the at least one surface comprises pores having a diameter of from 0.1 to 4 um.
3 . The cordierite sintered body of claim 1 having a density of from 2.55 to 2.63 g/cc.
4 . The cordierite sintered body of claim 1 having a volumetric porosity of from 0.1 to 4%, as calculated from density measurements performed in accordance with ASTM B962-17.
5 . The cordierite sintered body of claim 1 wherein the cordierite sintered body is substantially crystalline as determined by x ray diffraction.
6 . The cordierite sintered body of claim 1 having an arithmetical mean height (Sa) of 75 nm and less, on a surface as measured in accordance with ISO standard 25178-2-2012.
7 . The cordierite sintered body of claim 1 having a maximum height (Sz) of less than 5.5 um, according to ISO standard 25178-2-2012.
8 . The cordierite sintered body of claim 1 having a purity of from 99.9 to 99.995%, of the cordierite sintered body as measured using ICPMS methods.
9 . A photolithographic reticle comprising at least one layer of the cordierite sintered body according to claim 1 .
10 . The cordierite sintered body of claim 1 , wherein each of the powders, powder mixture and calcined powder mixture are free of naturally occurring materials comprising talc, kaolin, gibsite, dolomite, sepiolite, forsterite, and other clays and clay-based compounds.
11 . The cordierite sintered body of claim 1 , wherein the cordierite sintered body is free of naturally occurring materials comprising talc, kaolin, gibsite, dolomite, sepiolite, forsterite, and other clays and clay-based compounds.
12 . The cordierite sintered body of claim 1 , wherein the cordierite sintered body is free of glass forming constituents comprising alkali metal elements including lithium (Li), sodium (Na) and potassium (K), alkaline earth metal elements including calcium (Ca), strontium (Sr) and barium (Ba), transition metals including chromium (Cr), nickel (Ni), iron (Fe), copper (Cu), zinc (Zn), lead (Pb), rubidium (Rb) and metalloid elements including boron (B), germanium (Ge), arsenic (As), antimony (Sb) and bismuth (Bi).
13 . The cordierite sintered body of claim 1 , wherein the at least one surface comprises pores having a diameter of from 0.1 to 1 um.
14 . The cordierite sintered body of claim 1 having a density of from 2.62 to 2.63 g/cc, as measured in accordance with ASTM B962-17.
15 . The cordierite sintered body of claim 1 having a volumetric porosity of from 1.5 to 3.5% as calculated from density measurements performed in accordance with ASTM B962-17.
16 . The cordierite sintered body of claim 1 having an arithmetical mean height (Sa) of from 2 to 5 nm on a surface as measured in accordance with ISO standard 25178-2-2012.
17 . The cordierite sintered body of claim 1 having a maximum height (Sz) of from 0.3 to 1 um, according to ISO standard 25178-2-2012.
18 . The cordierite sintered body of claim 1 having a purity of from 99.95 to 99.995% relative to 100% purity of the cordierite sintered body as measured using ICPMS methods.