Area-Selective Deposition of Ruthenium Using Homometallic Precursor Inhibitor

Abstract

Area-selective deposition (ASD) using a precursor inhibitor (PI) is a promising alternative to self-assembled monolayer inhibitors due to a wide range of material selection and high process compatibility. In this study, bis­(ethylcyclopentadienyl)ruthenium [Ru­(EtCp)2] is introduced as a homometallic PI for the ASD of Ru. The chemical reactivity and steric hindrance between Ru­(EtCp)2, the Ru precursor, and H2O are theoretically calculated using density functional theory calculations and Monte Carlo simulations. The blocking property is related to the packing density of Ru­(EtCp)2 on the surface, and unoccupied sites degrade the blocking property. An additional H2O pulse is used to hydrolyze and remove the Et groups of Ru­(EtCp)2 to create more space for the additional adsorption of Ru­(EtCp)2. As a result, the packing density of Ru­(EtCp)2 PI increases, leading to an improvement in the blocking property. A single pulse of Ru­(EtCp)2 inhibits the growth of the Ru atomic layer deposition (ALD) film for 200 cycles, whereas Ru­(EtCp)2 with an additional H2O pulse inhibits the growth of the Ru ALD film for up to 300 cycles. Transmission electron microscopy results show that the Ru ASD thin films are purely metallic even after the degradation of Ru­(EtCp)2. This highlights the possibility of using homometallic PIs in future applications of metal ASD processes.

Organosulfide Inhibitor Instigated Passivation of Multiple Substrates for Area-Selective Atomic Layer Deposition of HfO2

“…Additionally, for statistical modeling of the DES inhibitor, an algorithm based on numerous random samplings was developed and compiled by using R open-source programming software. All details regarding the algorithm have been documented in previous studies conducted by our group. ,,, The MC simulations facilitated a clear understanding of the adsorption of the inhibitor on the surface, the total surface coverage, and further surface reactions. For the MC study, the DES molecular structure, Cu(111) and SiO 2 (001) 3D surfaces (Figure S6 in the Supporting Information) were created employing the R program.…”

Area Selective Deposition of Ru on W/SiO2 Nanopatterns via Sequential Reactant Dosing and Thermal Defect Correction

“…As devices shrink and metal spacing becomes more compact, challenges such as increased resistance and diminished metal film fill quality arise . Atomic layer deposition (ALD) offers a promising solution for metallic films with exceptional thickness control, uniformity, and conformality. − Area selective deposition (ASD) further refines this precision, enabling atomic-scale alignment with fewer steps on nanopatterns. − Ruthenium, known for its high wettability and low resistivity at smaller line width, emerges as a superior candidate for Cu diffusion barriers and replacements in metal interconnects . Its applications extend to gate metals in transistors and seed layers for electroplating. , …”