WAFER ALIGNMENT METHOD THAT IS INDEPENDENT OF THICKNESS AND UNDER-LAYER STRUCTURE IN 3-DIMENSIONAL IC INTEGRATION

摘要

PURPOSE: A wafer alignment method regardless of thickness and under-layer structure in 3-dimensional ic integration is provided to obtain direct economical effect by simplifying the steps of process. CONSTITUTION: A PMD oxide film is formed on a lower layer substrate by a chemical mechanical polishing(S601). The contact is formed through an etch back process(S603). The first metal wiring is formed in the front of the lower layer substrate(S605). The through via hole is formed in the front of the lower layer substrate(S609). The second metal wiring is formed in the front of the lower layer substrate(S611). The nitride film or the oxide film is laminated in the front of the lower layer substrate(S615). The lower layer substrate is bonded with the upper layer wafer(S617). The wafer alignment is formed on the upper layer wafer(S621). The upper layer wafer is patterned(S623). The three-dimensional integrated circuit is integrated(S625).