Standards Development

Scope

This part of IEC 62607 specifies a measurement protocol to determine the key control characteristics

– Optical properties

for metal-oxide interfacial devices by

– Spectroscopic ellipsometry

Ellipsometry measures a change in polarization as light reflects from a sample. The polarization change is represented as an amplitude ratio, Ψ, and the phase difference, Δ. Since the temperature history influences the optical properties, dielectric constant and oxygen-related peaks in the absorption, these changes are used to assess the thermal stability of the device.

– This method is applicable for evaluating the thermal stability of computing devices composed of the metal-oxide interfacial device, e.g., product-sum circuits, which record the learning process as the analog resistance change in which the dynamic behavio ur is influenced by dielectric properties observed as optical characteristics.

Purpose

Nano-enabled metal-oxide interfaces, such as an oxide nanolayer sandwiched by metal electrodes, are the essential components of IoT and AI devices for computing. Nano-enabled functions derived from the nanoscale metal-oxide interface and the oxide nanolayer appear, such as a significant change in electrical resistance and dielectric properties. As the metal-oxide interfacial devices becoming miniaturized, the evaluating methods are also becoming varied. In the present circumstances, there are no technical standards for objective and quantitative device durability assessment, typically thermal stability. Of the many evaluation items, thermal stability is a key and essential for development of the nano -enabled devices towards further social implementation. To evaluate the thermal stability of the devices, analysing optical properties can be one of the methods. For example, the shape of the optic al spectrum changes to reflect thermally induced changes in electronic states and dielectric properties.

Ellipsometry is a powerful optical technique to evaluate the dielectric properties of thin films. Ellipsometry can be used to characterize thickness, roughness, composition, crystalline nature, and other optical properties of nanomaterials. The signal depends on the change in the optical response of incident light that interacts with the metal-oxide interfacial device being investigated. Another important feature is that it is a non-destructive analysis method, which can be applied to quality control at man ufacturing sites.

This standard offers a measurement protocol using spectroscopic properties to evaluate the optical properties as the key control characteristics in nano -enabled metal-oxide interfacial devices. The described protocol does not cover methods of reliability testing, however, it can be utilized to evaluate the thermal stability through measurements of the optical properties.