Formation and microstructure of thin Ti silicide films for advanced technologies
We report on the solid-state reaction of thin PVD Ti films with in-situ doped Si & SiGe alloys using a combination of in-situ x-ray diffraction, sheet resistance, laser light scattering measurements and ex-situ x-ray pole figure analysis. Thin Ti films or thin bilayer films (Ni/Ti or NiPt/Ti) are found to be much more aligned with the underlying substrates. Millisecond laser anneals also lead to the introduction of strong in-plane texture.
Contact Metallization for Advanced CMOS Technology Nodes
Continuous CMOS scaling is being driven by innovation of novel device architectures to improve device performances at lower power consumption [1]. However, middle-of-the-line (MOL) continues to be a key performance and yield detractor for scaling. To alleviate these challenges, disruptive MOL architectures and materials are being proposed. At the ≤ 10NM node, significant differences are already seen in the MOL architecture and materials used by leading semiconductor companies [2]–[4]. This is expected to continue to smaller CMOS nodes where contacts represent significant contribution to external resistance (Rext). Figure 1 illustrates the impact of scaling on source/drain (S/D) contact vertical resistance, which can be quantified as the sum of silicide contact resistance (RC) and trench metallization resistance (RTs) [5]. It can be observed that at ≥ 20 nm trench bottom critical dimension (BCD), silicide contact resistance is the predominant contributor to the total vertical resistance. At these dimensions, it is critical to lower the specific contact resistivity $(\mathsf{p}_{\mathrm{C}})$ to reduce the vertical resistance. At narrow (< 20 nm) dimensions, it is observed that trench metallization resistance (for $\mathsf{p}_{\mathrm{C}}=0)$ contribution to the total vertical resistance starts to increase. In addition, below ~11 nm of BCD we see an inflection in resistance because of the change in transport from high resistive nucleation layers to liner/barrier materials. It should be noted that this figure was generated using resistance calculations for a simple trench dimension not specific to any technology and typical MOL materials.
Geologic proof on paleo-glaciation remains in Laoshan Mountain
Laoshan Mountain is the highest mountain in China coast.Various typical geomorphic features of glarosion,glacial deposition,rare glacial moraine coast and glacial moraine fans in east are well developed in Laoshan Mountain.Well preserved four glacial epochs are identified in Laoshan Mountain.In early Pleistocene,the altitude of snowline ranged from 60 m to 90 m in east.More than sixty paleo-glacial tongues were developed in Laoshan Mountain,some of them which located in east extended into the Yellow Sea.Sporopollen analysis indicates that the climate in Laoshan Mountain is very cold during the ice age.Multi-modal grain-size probability curves of the moraines are the typical characteristics of sediments deposited by glaciation.Regional landforms and climatic conditions are the key factors dominating the altitude of snowline during the ice age.