Area-Selective ALD of Ru on Nanometer-Scale Cu Lines through Dimerization of Amino-Functionalized Alkoxy Silane Passivation Films

Abstract

The selective deposition of materials on predefined areas on a substrate is of crucial importance for various applications, such as energy harvesting, microelectronic device fabrication, and catalysis. A representative example of area-confined deposition is the selective deposition of a metal film as the interconnect material in multilevel metallization schemes for CMOS technology. This allows the formation of multilevel structures with standard lithographical techniques while minimizing pattern misalignment and overlay and improving the uniformity of the structures across the wafer. In this work, area-selective deposition of Ru by atomic layer deposition (ALD) is investigated using alkoxy siloxane dielectric passivation layers. In this work, a comparison of several silane organic SAM precursors in terms of Ru ALD ASD performance is reported. The importance of the surface areal concentration of the passivation molecules is demonstrated. According to the in situ X-ray photoelectron spectroscopy film characterization, the ALD blocking layers derived from a (3-trimethoxysilylpropyl) diethylenetriamine (DETA) precursor have the ability to polymerize under ALD-compatible temperatures, such as 250 °C, which leads to a significant inhibition of Ru growth up to 400 ALD cycles. At the same time, the DETA layer can be selectively removed from the oxidized Cu surface by rinsing in acetic acid, which allows selective deposition of ca. 14 nm of Ru on Cu with no Ru detected on the DETA-coated surface by RBS. The approach is successfully tested on 50 nm halfpitch patterned SiO 2 /Cu lines.

Inherently Area-Selective Atomic Layer Deposition of Manganese Oxide through Electronegativity-Induced Adsorption

“…To elucidate the origin of selective growth, the density functional theory (DFT) and nudged elastic band (NEB) are adopted to calculate the decomposition energy and energy barriers of ALD precursors on Pt, Cu and SiO 2 surfaces, as shown in Figure 5a. On the SiO-OH surface, the following reactions between Mn(EtCp) 2 and surface are considered as Equation (2) [34][35][36]: According to the previous study, the following decomposition reactions on the surface of Pt and Cu are considered as Equation (3) [37,38]:…”

Additive Lithography–Organic Monolayer Patterning Coupled with an Area-Selective Deposition

“…15 There are, of course, a variety of methods to enable ASD, that include exploiting differences in surface reactivity, 11 the use of conventional resist materials, 16 amorphous carbon, 14,17 and other small molecules. 12,18 However, self-assembled monolayers (SAMs) exhibit some of the highest levels of selectivity. 19−25 SAMs are a distinct class of organic material that assemble from the surface adsorption and orientation of small molecules that form well-ordered crystalline monolayers.…”

Non‐self‐sustained electron beam RF‐generated plasma in application for functional surface pretreatment

“…An additional advantage of ASD is a possibility to grow materials in a bottom‐up fashion for future interconnect technology, which allows filling of narrow/high aspect ratio structures without the formation of voids and seams, which become a stringent problem when sub‐10‐nm CD structures are to be filled with deposition techniques. [ 1–4 ] The preliminary surface pretreatment by low‐energy ions or low‐energy ions with radicals can be used for this goal.…”