Localized charge trapping and lateral charge diffusion in metal nanocrystal-embedded High-κ/SiO2 gate stack

Abstract

In this work, we demonstrate a two-step analysis procedure that enables an in-depth understanding of the localized charge trapping and charge decay mechanisms in metal nanocrystal (MNC)-embedded high-κ/SiO2 gate stacks. The results clearly reveal that vertical charge loss and lateral charge diffusion are two competing mechanisms, and they can be identified by discharging current measurements at elevated temperatures and the Kelvin force microscopy characterization. It is found that the MNC with higher work function has a lower inter-dot charge tunneling probability, which is favorable for improved retention in memory applications. However, the vertical charge loss during the initial decay period is a trade-off and it could be minimized by using a dual-layer MNC structure.

In situ electron holography study of charge distribution in high-κ charge-trapping memory

“…Ramanathan et al 9 noted that the C-V curve could not perfectly reflect the chargetrapping phenomena because of the complexity of test environment. Recently, several types of scanning probe microscopy (SPM), such as electrostatic force microscope 10 , Kelvin force microscope 11 , scanning capacitance microscope 12 and conductive atomic force microscope 13 , have been used to profile the charge distribution in CTM with tens of nanometre resolution. SPM can track the lateral charge map and diffusion process but the working mode and the limited spatial resolution impede it to distinguish the vertical location of the trapped charges, which have an impact significantly on the performance of the device.…”

Tailoring by AgNPs of the Energetics of Charge Carriers in Electrically Insulating Polymers at the Electrode/Dielectric Contact

“…In the last decade, electrical modes derived from Atomic Force Microscopy (AFM), like Kelvin Probe Force Microscopy (KPFM) [9], [10], [11] and Electrostatic Force Distance Curve (EFDC) [12] largely advanced on the subject. They became indispensable to provide information on the density profiles of injected charges and the dynamics of charge injection, trapping, transport and decay in dielectrics [9], [10], [11], [12], [13], [14], [15], [16], [17]. Additional constraints, like thermal activation of trapped charges can also be accounted for in the analyses of charge transport when applying these methods [17].…”

Space Charge at Nanoscale: Probing Injection and Dynamic Phenomena Under Dark/Light Configurations by Using KPFM and C-AFM

“…Here, the main charge release mechanism is the volume one which is ascribed to high conduction during the injection process [66]. Concerning floating gate MOS memories, a thin dielectric layer with embedded nanoparticles [77] or quantum dots appears promising for the device performance in terms of charging and retention times [78]. Lwin et al demonstrated that the work function of metallic nanoparticles has a strong influence on the charge decay in the device active layer [77].…”