Method of the simultaneous formation for the storage node contacts, bit line contacts, and the contacts for periphery circuits

Abstract

A dynamic random access memory device comprises a substrate, a plurality of active regions, a plurality of substantially parallel word lines, a plurality of substantially parallel bit lines, a plurality of unitary bit line contacts, a plurality of storage nodes, and a plurality of unitary storage node contacts. The unitary bit line contacts and the unitary storage node contacts can be formed simultaneously and can interconnect the bit lines and the active regions, and the storage nodes and the active regions respectively. The bit line contacts can also be used for the contacts for the periphery circuitry, and the depth between the periphery circuit contacts to the substrate is sufficiently shallow such that good ohmic contacts can be formed in the periphery circuit. Further, a special pattern mask is employed to form the bit line contacts and the storage node contacts simultaneously, in order to reduce manufacturing costs. The special pattern can be longer than the active regions to prevent short circuits due to photolithography misalignment errors.