Cross leakage of capacitors in DRAM or embedded DRAM

摘要

A method of forming stacked capacitors for a DRAM structure. A thin layer of poly is deposited over the inside surface of the crown holes; the columns of the crown holes form the insulation between the DRAM capacitors. High temperature oxidation is performed on the exposed surface of this layer of poly creating thermal oxide. An anisotropic etch of the surface of the thermal oxide creates a thermal oxide film on the sidewalls of the inter-capacitance insulation. This thermal oxide film is positioned between the capacitors of the DRAM structure. It has superior film quality and as such reduces leakage current between DRAM capacitors. The bottom electrode for the capacitor is formed, ONO is grown on the exposed surface of the bottom electrode (forming the dielectric of the capacitor) after which the top electrode of the capacitor cell is formed.