Method for forming semiconductor structure with improved isolation between two layers of polycrystalline silicon

摘要

In a field effect device such as a charge coupled device or field effect transistor in which at least two levels of polycrystalline silicon conductors are used; these two levels of polycrystalline silicon are isolated from one another with a dielectric layer. Disclosed is a composite dielectric layer formed either by in situ oxidation of the first polycrystalline silicon layer plus chemical vapor deposited silicon dioxide or, in the alternative, the composite dielectric layer is formed by a phosphosilicate glass layer with thermal reoxidation of the first polycrystalline silicon layer.