Dual Dielectric Insulation Improvement
Original Publication Date: 1985-Sep-01
Included in the Prior Art Database: 2005-Feb-19
A modification has been proposed for the MLM and/or L2/N2-type insulator schemes which would improve the barrier insulator's ability to perform its function, which is to conformally coat all projections and base insulator holes. Evidence exists that hole-type defects generated by the photo process in both the MLM insulator (etchback) and the L2/N2 process (first via) are not totally insulated by the 2850-angstrom Si3N4 layer which is deposited. Application of a planarizing spin-on dielectric layer prior to the silicon nitride deposition would result in process and reliability improvements. Compass T-2 runs have ILS To defect densities as high or higher than the Purdue composite insulator. PYATS EWR's additionally indicate that the "buried photo defects" may be very leaky (<50KL).