Are DRAM capacitors reaching the scaling limit?

DRAM capacitors are reaching the scaling limit and new approaches are necessary to enable further reduction of the physical thickness of the capacitor dielectric. The conduction band offset (CBO) of a platinum noble metal electrode on atomic layer deposited ZrO 2 /Al 2 O 3 /ZrO 2 is evaluated and compared to a titanium nitride electrode.

Does barrier height affect dielectric scaling?

The barrier height difference between the two electrodes is evaluated in comparison with a previously reported model. Finally, the impact of an increased barrier height on dielectric scaling will be discussed based on a leakage current simulation of a ZrO 2 capacitor.

Is giant dielectric a grain boundary or a barrier layer capacitance?

The giant-dielectric phenomenon is therefore attributed to a grain boundary (internal) barrier layer capacitance (IBLC) instead of an intrinsic property associated with the crystal structure.

Does a top electrode deposition increase the thickness of the interfacial tion layer?

With this, we confirmed the above-discussed hypothesis that a top electrode deposition increases the thickness of the interfacial TiON layer at the bottom electrode by pulling out oxygen from the ZrO 2 and creating vacancies in the dielectric close to the bottom electrode .

Does conduction band offset affect leakage current?

This leads to a decrease of the tunneling probability and the Poole–Frenkel current component. In addition, leakage current simulations showed that an increasing conduction band offset results in a decrease of the F-N tunneling leakage at high electric field.

How to scale down ZrO 2 dielectric for future DRAM capacitors?

Therefore, conduction band offset improvements by introduction of inert metal electrodes with higher CBO represent one of the most effective ways to scale down the ZrO 2 dielectric for future DRAM capacitors. Kil DS, Song HS, Lee KJ, Hong K, Kim JH, Park KS, et al. Proceedings of the symposium on VLSI technology digest of technical papers.