Search

Atmospheric pressure plasma deposition (APPD) of poly(ethylene oxide) (PEO)‐like antifouling coatings provides an attractive way to reduce biofouling for reliable biosensor operation. Cold atmospheric pressure plasma jets are designed to operate in open air. This paper demonstrates the impact of open‐air processing on the composition and properties of PEO‐like coatings by APPD with vinyl ether precursors. The open‐air environment inhibits polymerization as indicated by low deposition rates, oxygen incorporation in the coatings, and instability of the coatings in water. The composition and stability of the coatings improve by appropriate nozzle design and by deposition in an environment with lower air content. The resulting PEO‐like coatings are stable and antifouling for an antibody solution and inhibit adhesion of human fibroblast cells. [ABSTRACT FROM AUTHOR]

Area‐selective deposition (ASD) is a bottom‐up technique that provides numerous opportunities for nanoelectronic device fabrication. For example, advanced nano‐interconnect structures with barrierless metals like Ru in the contact holes can be created by Ru ASD with the bottom metals as growth surfaces and dielectrics as non‐growth surfaces. This work investigates Ru ASD by chemical vapor deposition (CVD) on industrially relevant substrates and nanopatterns and reveals how selectivity and growth rate are modulated by the CVD conditions and type of nanopattern. For low‐k dielectric/Cu substrate combinations, the selectivity reverses from metal‐on‐metal to metal‐on‐dielectric upon only changing the CVD co‐reagent from H2 to NH3. In contrast, NH3 is the preferred co‐reagent for SiO2‐TiN line patterns with critical dimension (CD) of 40 nm due to the more favorable adsorption and diffusion kinetics that cause growth rate and selectivity enhancement. Consistent with a diffusion‐mediated mechanism, the growth rate enhances even more for Ru CVD on nanoscale contact holes with CD of 10.5 nm, becoming 2.4 times higher as compared to unpatterned substrates. Thus, the ASD process changes drastically when pattern dimensions reach the nanoscale. The reported insights facilitate rational design of metal ASD processes for multiple applications in nanofabrication. [ABSTRACT FROM AUTHOR]

Area‐selective deposition (ASD) shows great promise for sub‐10 nm manufacturing in nanoelectronics, but significant challenges remain in scaling to ultrasmall dimensions and understanding feature‐dependent nonuniformity and selectivity loss. This work addresses these problems by simultaneously quantifying uniformity and selectivity for passivation/deposition/etch supercycles in 45 nm half‐pitch TiN/SiO2 line/space patterns. This work employs three selective processes that are uniquely suited for supercycle processing: dimethylamino‐trimethylsilane (DMA‐TMS) inhibition, TiO2 atomic layer deposition (ALD), and HBr/BCl3 plasma etch. The DMA‐TMS inhibition selectively passivates the SiO2 nongrowth surface without affecting deposition on the TiN and TiO2 growth surfaces. The plasma etch removes TiO2 defect particles at a faster rate than the conformal TiO2 film or SiO2 lines. Using three supercycles of this process, this work demonstrates 8 nm of TiO2 with 88% uniformity and ≈100% selectivity according to transmission electron microscopy (TEM), a 2×improvement in film thickness from previous reports in similar nanoscale patterns. Integrated consideration of uniformity and selectivity at specific feature scales will facilitate the effective design of selective deposition processes for nanoscale electronic devices. [ABSTRACT FROM AUTHOR]

Area‐selective deposition (ASD) is a promising bottom‐up approach for fabricating nanoelectronic devices. However, a challenge is to prevent the undesired growth of nanoparticles in the nongrowth area. This work uses kinetic Monte Carlo (KMC) methods to investigate the defectivity in ruthenium ASD by (ethylbenzyl)(1‐ethyl‐1,4‐cyclohexadienyl)Ru/O2 (EBECHRu) atomic layer deposition (ALD) in line‐space nanopatterns with different dimensions. Ru ASD is governed by adsorption as well as diffusion. The defectivity depends on the pattern dimensions, as nanoparticles can diffuse and reach the interface with the growth area where they aggregate. For linewidths of 50 nm and smaller, all Ru adspecies are captured at the growth interface before growth by precursor adsorption is catalyzed. The synergetic effect of diffusion and size‐dependent reactivity reduces defectivity below 1010 Ru atoms cm−2 for at least 1000 ALD cycles. This is more than 1000 times lower than for patterns with a linewidth of 200 nm and larger, where the Ru content decreases significantly only near the interface with the growth surface. The predicted depletion zone is confirmed by experiments in nanoscale line‐space patterns. Overall, this mechanism results in smaller and fewer Ru nanoparticles for smaller patterns, facilitating the development of passivation‐deposition‐etch ASD processes for nanoelectronic device fabrication. [ABSTRACT FROM AUTHOR]

In this paper, the deep levels found by Deep-Level Transient Spectroscopy in Si-O superlattices (SLs) on n-type silicon are reported. Samples have been grown with one, two or five silicon-oxygen layers, separated by 3 nm of silicon. A Cr Schottky barrier (SB) is thermally evaporated on top of the SL. Similar as for p-type silicon, no deep levels have been found for a bias pulse in depletion, while a broad distribution of electron traps shows up when pulsing into forward bias. At the same time, these bands are absent in a zero SL reference sample. Similar as for the p-type results, the trap filling of the electron states exhibits a logarithmic capture. The possible origin of this slow filling will be discussed. [ABSTRACT FROM AUTHOR]

The presence of deep levels in a silicon-oxygen (Si-O) superlattice (SL) deposited on p-type silicon substrates has been investigated by deep-level transient spectroscopy (DLTS) on thermally evaporated Cr Schottky barriers (SBs). The SLs have been fabricated with different thicknesses of the silicon interlayers, formed by chemical vapor deposition. It is shown that a broad band of hole traps is present near the surface of the SB, which is associated with the SL. In addition, the activation energy corresponding with the peak maximum shifts to higher values with respect to the valence band and gives rise to a higher trap concentration with increasing silicon interlayer thickness. It is proposed that these states are associated with the structural defects found in similar SL structures, that is, with the epitaxial quality and not with the SiO bonds in the atomic layers. The change in the DLT-spectra with silicon thickness could be related with the transformation of the structural defects from small self-interstitial clusters to stacking faults. [ABSTRACT FROM AUTHOR]

The atomic layer deposition (ALD) of Gd2O3 from tris(isopropyl-cyclopentadienyl) gadolinium (Gd(iPrCp)3) and O3 is studied as a function of the O2/N2 ratio used to generate O3. ALD using O3 with low N2 content leads to the formation of a hydroxyl-terminated surface after combustion reactions during O3 exposure followed by proton transfer and ligand release during the Gd(iPrCp)3 half cycle. This condition leads to the presence of parasitic chemical vapor deposition (CVD) due to the hygroscopicity of Gd2O3. By contrast, long O3 pulses with high N2 content lead to the dehydroxylation of the surface and to the suppression of both the proton transfer during the Gd(iPrCp)3 half cycle as well as the parasitic CVD reactions. [ABSTRACT FROM AUTHOR]

The atomic layer deposition (ALD) of Ta2O5 and TaSiO x from TaCl5, SiCl4, and H2O is reported. Both processes are influenced by the concomitant etching of Ta2O5 and TaSiO x by TaCl5. The optimum deposition temperature is found to be 250 °C for both Ta2O5 and TaSiO x. For lower deposition temperatures, the large Cl contamination leads to poor dielectric properties of the films, whereas higher temperatures lead to poor within-wafer (WiW) thickness non-uniformity due to etching. Si incorporation is limited to Si/(Si + Ta) ∼ 0.65 because of the slow adsorption kinetics of SiCl4 on SiOH-terminated surfaces. Under optimum conditions, amorphous films with good dielectric quality are obtained. [ABSTRACT FROM AUTHOR]

Area‐selective deposition (ASD) receives increasing attention as a bottom‐up approach for nanoelectronic device fabrication. Uptake of ASD is however limited by defects, which manifest as undesired particle growth on the nongrowth surface. A defect mitigation solution is demonstrated for Ru ASD on TiN/SiO2 nanopatterns by making use of the size‐dependent Ru nanoparticle reactivity. During the initial stages of 1‐(ethylbenzyl)‐1,4‐(ethylcyclohexadienyl)ruthenium and oxygen (EBECHRu/O2) atomic layer deposition (ALD) on dielectrics, Ru particles are too small to catalytically dissociate oxygen, and their growth is suppressed. This phenomenon creates an ASD process window in which particles can be completely etched while retaining the integrity of the ASD pattern on a TiN growth surface. Decreasing the ALD temperature strongly suppresses defect growth, which can be used to expand the process window for ASD. The ASD process window is confirmed by self‐focusing secondary ion mass spectrometry (SF‐SIMS) with its low limit of detection while analyzing 104 structures simultaneously. No defects are detected for Ru ASD on 36 nm TiN/SiO2 patterns by SF‐SIMS. The Ru ASD process is applied for bottom‐up block patterning and functional hardmask patterns are obtained on 300 mm wafers. The approach followed in this work can produce defect‐free ASD processes for a wide variety of applications. [ABSTRACT FROM AUTHOR]

Understanding the growth mechanisms during the early stages of atomic layer deposition (ALD) is of interest for several applications including thin film deposition, catalysis, and area‐selective deposition. The surface dependence and growth mechanism of (ethylbenzyl)(1‐ethyl‐1,4‐cyclohexadienyl)ruthenium and O2 ALD at 325 °C on HfO2, Al2O3, OH, and SiOSi terminated SiO2, and organosilicate glass (OSG) are investigated. The experimental results show that precursor adsorption is strongly affected by the surface termination of the dielectric, and proceeds most rapidly on OH terminated dielectrics, followed by SiOSi and finally SiCH3 terminated dielectrics. The initial stages of growth are characterized by the formation and growth of Ru nanoparticles, which is mediated by the diffusion of Ru species. Mean‐field and kinetic Monte Carlo modeling show that ALD on OSG is best described when accounting for (1) cyclic generation of new nanoparticles at the surface, (2) surface diffusion of both atomic species and nanoparticles, and (3) size‐dependent nanoparticle reactivity. In particular, the models indicate that precursor adsorption initially occurs only on the dielectric substrate, and occurs on the Ru nanoparticles only when these reach a critical size of about 0.85 nm. This phenomenon is attributed to the catalytic decomposition of oxygen requiring a minimum Ru nanoparticle size. Atomic layer deposition of ruthenium on dielectrics is governed by cyclic nanoparticle generation, surface diffusion, and aggregation of nanoparticles. The nanoparticle reactivity is strongly size‐dependent. This insight in the growth mechanism can help tune the morphology of the deposited material for several applications including thin film deposition, catalytic nanoparticles, and area‐selective deposition. [ABSTRACT FROM AUTHOR]