Reliability and Characterization of Composite Oxide/Nitride Dielectrics for Multi‐Megabit Dynamic Random Access Memory Stacked Capacitors
Year: 1991
Type: article
Abstract: The reliability and electrical properties of planar and 3D interpoly oxide/nitride films stacked on multi‐megabit dynamic random access memory (DRAM) array topography are reported to determine their thinning and capacitance limits. A compromise between reliability, leakage current, and storage capacity is proposed for oxidized low‐pressure chemical vapor deposited nitride layers with different nitride thicknesses, oxidation conditions, and top/bottom polysilicon doping levels. Capacitance, leakage current, and time‐dependent dielectric breakdown measurements show that thinner nitride layers with longer oxidation times provide the maximum lifetime and capacitance. However, the nitride thinning is limited when leakage current by Poole‐Frenkel or Fowler‐Nordheim emission occurs. For 5 V operated high‐density DRAMs, nitride layers as thin as 7 nm, giving a capacitance of 6 fF/μm 2 present the optimum conditions. For 3.3 V operations, films as thin as 4–5 nm, giving a capacitance of 9 fF/μm 2 , can be expected.
DOI: 10.1149/1.2085923
Institution: Micron (United States)
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2034077653