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Triblock polymers, poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEO-b-PPO-b-PEO), are used as molecular templates in poly(methyl silsesquioxane) (MSQ) matrixes to fabricate nanoporous organosilicates for low dielectric constant applications. The results show that aggregation of block copolymers in the MSQ matrix can be prevented with the fast solvent evaporation which accompanies spin casting. Solid-state NMR shows that the triblock copolymer microphase-separates from the MSQ during a curing step, resulting in polymer domain size in the range of 3−15 nm, depending upon the polymer composition and loading percentage. When the films are heated to 500 °C, extremely small pores (2−6 nm) are generated, which are studied by small angle neutron scattering and positronium annihilation lifetime spectroscopy. These materials attain ultralow dielectric constants (k ≈ 1.5) with good electrical and mechanical properties.

Abstract: This paper presents the effects of annealing, performed over a temperature range from 200�C to 400�C, on the surface microstructural evolution and the electromigration reliability of electroplated Cu films. After annealing, a substantial increase in surface roughness was observed, while variations in mean grain size and nanoindentation hardness were minor. Given the annealing temperature, the surface roughness was larger for the films annealed in forming gas, due to the existence of hydrogen. In particular, the films annealed at 400�C in forming gas demonstrated severe grain-boundary grooving and surface voiding. The defective nature of the annealed surface can be alleviated by chemical-mechanical polishing (CMP), when annealing is conducted prior to the CMP. However, it appears that a sequential thermal excursion at relatively high temperatures re-aggravates the integrity of the Cu surface. This argument may be supported by the electromigration-test results on dual-damascene interconnects fabricated using two different thermal profiles. The electromigration lifetimes were longer by more than a factor of two for the interconnects that skipped a post-passivation anneal at 400�C. The experimental evidence presented in this work suggests that controlling the integrity and quality of the Cu surface is an important step in ensuring good electromigration reliability.

Abstract: Continued shrinking of feature sizes in integrated circuits has raised increasing reliability concern. In order to achieve higher packing density, interconnects are migrating toward borderless contacts and vias. The penalty with the absence of metal extension, however, is the decrease in electromigration lifetimes. The issue is particularly critical when there is a misalignment between the contact and metal line, which may occur due to process variability. In this paper, we studied the effect of misalignment on the electromigration lifetimes for bordered and borderless contacts. We found that the misalignment effect becomes more pronounced in borderless contacts. We also studied the case of multiple contact configuration. The results indicate that electromigration lifetimes increase with increasing number of contacts in series. The experimental data is consistent with finite element modeling results.

Nanoelectronics require the introduction of several new uncharacterized material(s) combinations and new processing techniques. The critical metrology and characterization needs of the nanoelectronics industry are being addressed with a broad range of development programs at the National Institute of Standards and Technology (NIST). In this paper, we provide an overview of the recent advances in nanoelectronics enabling metrology developments at NIST. We will discuss a broad range of new techniques, equipment and infrastructure that are being developed to enable atomic and nano-scale measurements. Examples include, but are not limited to: high resolution, low noise techniques and infrastructure for nanoscale chemical analysis; metrology for characterizing device and material intrinsic reliability; electrical, optical and physical characterization of novel materials; and monitoring of processes.

Tribological properties at the polishing interface during chemical mechanical polishing (CMP) in different slurry chemical environments need to be studied in greater detail, to understand the mechanism and science of CMP. The chemical reactions in different environments significantly affect the actual tribological behavior at the interface. In the present research, slurry temperature, oxidizer percentage and complexing agent concentrations in the slurry are varied and their effect on the tribology at the interface on polyurethane pads has been studied. Specifically, the main goal of this research is to develop fundamental understanding about the role of coefficient of friction in CMP and the effect of slurry characteristics on the tribology at the interface. From the results the effect of slurry temperature was found to be very weak when compared to the other process parameters such as pressure and velocity.

It is shown that the reduced oxidant used to generate the mixed‐valence species (I) serves as necessary "cofactor" in the observation of an intervalence transfer (IT) band.