Analysis of glassy phase formed at interface of metallized alumina for semiconductor substrate by ICP-AES after selective dissolution

Abstract

Elemental analysis of a glassy phase at metallized alumina interface by ICP-AES following selective dissolution was studied. A test sample was prepared by printing tungsten paste on a green sheet (92% Al2O3-5.2% SiO2-2% MgO-0.8% CaCO3) and by sintering at 1570°C. The glassy phase formed was exposed by removing the metal layer by anodic stripping in 10% NaOH solution. Selective decomposition conditions for the glassy phase with sulfuric acid were studied using a Teflon pressurized decomposition vessel. The optimum decomposition was achieved at 200°C for 1.5 h with (1 + 5) sulfuric acid. In the ICP-AES determination, sulfuric acid reduced the emission intensities of Al, Si, Mg, Ca by approximately 10%. In order to compensate for the matrix effect, the use of a standard solution containing the same concentration of sulfuric acid as that in sample solution, 10 [Ag/ml of Al and Si, and 3 µg/ml of Mg and Ca was required. Variation of the total dissolved amount per sample was within 0.1 mg (n = 5) and those of the chemical composition were ± 1% for Al2O3 and SiO2, ± 0.5% for MgO and CaO by the proposed method. © 1990, The Japan Society for Analytical Chemistry. All rights reserved.