Soot Bonding Process and its Application to Si Dielectric Isolation

A dielectric isolated substrate produced by bonding two silicon substrates with Si—B—O soot particles generated by a flame hydrolysis reaction is introduced. There are three steps in the production process: spraying Si—B—O soot on a flat or a grooved silicon substrate, positioning a support substrate, and sintering. The grooves can be filled and the two substrates bonded at the same time and without voids. Experimentally fabricated large scale integrated circuits have good performance characteristics, over the whole substrate. This method can produce a 6 in. diam or larger dielectric-isolated substrate, which cannot be created with the conventional polysilicon deposition method.