Method for preparing a memory device with air gaps for reducing capacitive coupling

Abstract

The present application provides a method for preparing a memory device. The method includes: forming an active region in a substrate, forming a word line in the substrate, wherein the word line is intersected with the active region; forming a contact structure on the substrate, wherein the contact structure is located at a side of the word line, and electrically connected to the active region; sequentially forming a first conductive layer and a second conductive layer over the substrate, wherein the contact structure is covered by the first and second conductive layers; patterning the first and second conductive layers to form a conductive pillar and a landing pad, respectively, wherein the conductive pillar is overlapped with and electrically connected to the contact structure, the landing pad covers and electrically connects to the conductive pillar, and a sidewall of the conductive pillar is laterally recessed from a sidewall of the landing pad; and forming a dielectric layer to laterally surround the conductive pillar and the landing pad.