Improved leakage current properties of ZrO2/(Ta/Nb)Ox-Al2O3/ZrO2 nanolaminate insulating stacks for dynamic random access memory capacitors

Dielectric Constant Enhancement and Leakage Current Suppression of Metal–Insulator–Metal Capacitors by Atomic Layer Annealing and the Capping Layer Effect Prepared with a Low Thermal Budget

“…The outcomes demonstrate that the capping of the TiN top electrode and the ALA treatment lead to significant ZrO 2 crystallization in the ZAT sample prepared at a low process temperature (300 °C) without being treated with any postannealing process. It is worth noting that the postannealing temperature for crystallization of ZrO 2 in MIM structures is as high as 600 °C. ,− Therefore, the TiN capping and the ALA treatment are effective to reduce the thermal budget to meet the requirement (<400 °C) of the BEOL process.…”

“…Hence various oxide stack structures, such as ZrO 2 /Al 2 O 3 /ZrO 2 (ZAZ), , ZrO 2 /SiO 2 /ZrO 2 (ZSZ), , ZrO 2 /Y 2 O 3 /ZrO 2 (ZYZ), and ZrO 2 /La 2 O 3 /ZrO 2 (ZLZ), have been proposed and investigated, in which the ZAZ structure is the most widely used oxide stack in MIM capacitors in recent years. , The introduction of an Al 2 O 3 interlayer into the oxide stack can suppress the leakage current. , However, it results in a decrease in the capacitance . The crystallinity of ZrO 2 on the upper layer of Al 2 O 3 is deteriorated by the Al 2 O 3 interlayer, resulting in a decrease in the dielectric constant. , In order to get a good crystallinity of ZrO 2 overlying the Al 2 O 3 interlayer, the postannealing treatment at a temperature of ∼600 °C is usually needed. ,− Nevertheless, the high-temperature annealing leads to an increase in leakage current as a result of the generation of grain boundaries, which hinders the reduction of the oxide thickness in the MIM structure for further EOT scaling . Besides, this high annealing temperature is highly unfavorable for the BEOL process in advanced semiconductor technology nodes where the process temperature is limited to below 400 °C. , On the other hand, the use of a titanium nitride (TiN) bottom electrode in the MIM structure gives rise to the formation of an interfacial layer when depositing oxide, which causes the degradation of electrical performance. , In addition, the relatively low work function of TiN brings about a high leakage current in the MIM structure .…”

Toward Low-Thermal-Budget Hafnia-Based Ferroelectrics via Atomic Layer Deposition

“…This concept is based on the superior characteristics of ZrO 2 films processed via the low-temperature ALD process at 300 °C (e.g., good crystallinity and predominantly o/t/c-phases). The HZO-based MFM capacitors with a ZrO 2 nucleation layer exhibited the improvement of their ferroelectricity, while those with an amorphous Al 2 O 3 layer showed smaller 2 P r compared to the conventional HZO-based MFM capacitors. − ,− Here, the effect of the ZrO 2 layer on the ferroelectricity of the MFS structure was investigated. Figure a,b shows cross-sectional TEM images of MFS capacitors without ZrO 2 (w/o) and ZrO 2 -10 nm following the PMA process at 300 °C.…”

Investigation of Leakage Current in Micro M-I-M Structure Using Multilayer High-K Dielectric Materials with COMSOL Multiphysics

“…A micro M-I-M capacitor is a passive two-terminal component made up of two conducting parallel plates separated by a dielectric insulating substance. High dielectric (K) insulators have been extensively investigated as dielectrics for storage, flash memory, Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), and dynamic random access memory, as well as as a channel for Oxide Thin Film Transistor (oxide-TFT) [12].…”