Determination of optical constants of thin films in the EUV.

The determination of fundamental optical parameters is essential for the development of new optical elements such as mirrors, gratings, or photomasks. Especially in the extreme ultraviolet (EUV) and soft x-ray spectral range, the existing databases for the refractive indices of many materials and compositions are insufficient or are a mixture of experimentally measured and calculated values from atomic scattering factors. Since the physical properties of bulk materials and thin films with thicknesses in the nanometer range are not identical, measurements need to be performed on thin layers.

Influence of the Chalcogen Element on the Filament Stability in CuIn(Te,Se,S)/AlO Filamentary Switching Devices.

In this paper, we report on the use of CuInX (X = Te, Se, S) as a cation supply layer in filamentary switching applications. Being used as absorber layers in solar cells, we take advantage of the reported Cu ionic conductivity of these materials to investigate the effect of the chalcogen element on filament stability. In situ X-ray diffraction showed material stability attractive for back-end-of-line in semiconductor industry.

Atomic Layer Deposition of Ruthenium with TiN Interface for Sub-10 nm Advanced Interconnects beyond Copper.

Atomic layer deposition of ruthenium is studied as a barrierless metallization solution for future sub-10 nm interconnect technology nodes. We demonstrate the void-free filling in sub-10 nm wide single damascene lines using an ALD process in combination with 2.5 Å of ALD TiN interface and postdeposition annealing.

Understanding the Dual Nature of the Filament Dissolution in Conductive Bridging Devices.

The formation and rupture of conductive filaments (CFs) inside an insulating medium is used as hardware encoding of the state of a memory cell ("1" - "0") in filamentary-based conductive bridging memories. Currently accepted models explain the filament erase (reset) as the subtraction of conductive metal atoms from the CF; however, they do not fully account for the rich set of phenomena experimentally observed during the reset. The details of the filament erase are unraveled on the nanometer scale by means of an atomic force microscopy-based tomography technique enabling the 3D observation of erased CFs.

Combinatorial Study of Ag-Te Thin Films and Their Application as Cation Supply Layer in CBRAM Cells.

In this work, we investigate binary Ag-Te thin films and their functionality as a cation supply layer in conductive bridge random access memory devices. A combinatorial sputter deposition technique is used to deposit a graded Ag(x)Te(1-x) (0 < x < 1) layer with varying composition as a function of the position on the substrate. The crystallinity, surface morphology, and material stability under thermal treatment as a function of the composition of the material are investigated.

Three-dimensional observation of the conductive filament in nanoscaled resistive memory devices.

The basic unit of information in filamentary-based resistive switching memories is physically stored in a conductive filament. Therefore, the overall performance of the device is indissolubly related to the properties of such filament. In this Letter, we report for the first time on the three-dimensional (3D) observation of the shape of the conductive filament.

Switching mechanism and reverse engineering of low-power Cu-based resistive switching devices.

In the recent past, filamentary-based resistive switching devices have emerged as predominant candidates for future non-volatile memory storage. Most of the striking characteristics of these devices are still limited by the high power consumption and poor understanding of the intimate resistive switching mechanism. In this study, we present an atomic scale study of the filament formation in CuTe-Al2O3 by using a conductive scanning probe tip to analyse the shape and dimensions of the filament.

Ultrathin NiGe films prepared via catalytic solid-vapor reaction of Ni with GeH(4).

A low-temperature (225-300 °C) solid-vapor reaction process is reported for the synthesis of ultrathin NiGe films (∼6-23 nm) on 300 mm Si wafers covered with thermal oxide. The films were prepared via catalytic chemical vapor reaction of germane (GeH4) gas with physical vapor deposited (PVD) Ni films of different thickness (2-10 nm). The process optimization by investigating GeH4 partial pressure, reaction temperature, and time shows that low resistive, stoichiometric, and phase pure NiGe films can be formed within a broad window.

Influence of carbon alloying on the thermal stability and resistive switching behavior of copper-telluride based CBRAM cells.

We report the improved thermal stability of carbon alloyed Cu0.6Te0.4 for resistive memory applications.