Passivation and VLSI packaging glasses with low flow points

Abstract

Viscosity points, molar polarizability and electrical properties for ZnO-B2O3-SiO2-P2O5 and PbO-B2O3-SiO2-Al2O3 glass systems were investigated in order to apply them as passivation and VLSI ceramics packaging sealing glasses. It was found that the MOS capacitors passivated by ZnO-bascd glasses with Tf (flow point) = 708-750 °C and Pm (molar polarizability) = 0.368-0.397 exhibit normal C-V curves. ZnO-based glasses having low polarizability are applicable to device passivation, where a relatively low flow point is required. PbO-based glasses with high PbO-contcnt showed a low flow point and their amorphous state was more stable than that for ZnO-based glasses. However, the C-V curves for MOS capacitors, passivated by the highly polarizablc PbO-based glasses, were shifted towards high voltage. These glasses arc particularly suitable for VLSI package low temperature sealing with Tf=560 °C. © 1986 Elsevier Science Publishers B.V. (North-Holland Physics Publishing Division).