Dry-Etchable Molecular Layer-Deposited Inhibitor Using Annealed Indicone Film for Nanoscale Area-Selective Deposition

Abstract

In semiconductor production, the technology node of a device is becoming extremely small below 5 nm. Area selective deposition (ASD) is a promising technique for creating improved overlay or self-alignment, remedying a conventional top-down method. However, the conventional materials and process (selfassembled monolayer, polymer and carbon film fabricated by chemical vapor deposition, and spin coating) for ASD are not suitable for highly conformal deposition. Thus, we investigated a new strategy to deposit conformal films in ASD by molecular layer deposition (MLD). The MLD processes were conducted for an indicone film deposited by INCA-1 (bis(trimethysily)amidodiethyl indium) and hydroquinone (HQ), as well as an alucone film deposited by TMA (trimethylaluminum) and HQ. After thermal heat treatment of the MLD films, variations in thickness, refractive index, and constituent elements of the annealed MLD films were investigated. The indicone film was used as an inhibiting layer for ASD and was etchable with a dry-etching process. The reactive ion etching process on annealed indicone film was optimized according to plasma power, gas concentration, and working pressure. Ruthenium (Ru) ALD was then performed on the annealed MLD films to investigate nucleation delaying cycles and inhibiting properties. A patterned substrate with an MLD/Si line was created via the RIE process, which was allowed to observe the selectivity of the annealed MLD films. In addition, a patterned substrate of SiO 2 /annealed indicone/Mo was used to investigate the Ruselective ALD at the nanoscale. The Ru thin film was selectively deposited on the Mo side-wall surface of a 3D trench structure. The growth of the Ru film was inhibited selectively on an annealed indicone surface of approximately 5 nm.

Review of molecular layer deposition process and application to area selective deposition via graphitization

“…In particular, various metalcones have exhibited structural rearrangement during the annealing process after deposition. 52,53,[168][169][170] The characteristics of increasing the orientation of graphitic carbon as the temperature increases have been reported in various metalcones. [171][172][173] The fabrication of graphitic carbon depends on temperature, and the D and G peaks are observed in Raman spectra, beginning at 450 °C in Fig.…”

“…This is because even with the same metalcone, graphitization may or may not occur depending on whether the organic reactant used is "Aliphatic" or "Aromatic." For metalcones manufactured using an aromatic ring as an organic precursor, graphitization proceeds through high-temperature annealing, 50,52,53) and the inhibition property can be activated by removing surface functional groups. 50,51) Not only organic reactants but also metal elements can be considered.…”

“…Park's group conducted various investigations about the film properties and applications of indicone films made with bis(trimethylsily)amidodiethylindium (INCA) and HQ. 51,53,[62][63][64] Lee et al 62) demonstrated an MLD of indicone first, an indium-based polymer. Incorporating indium in the organic layer may prevent mismatching of the electronic structure with In 2 O 3 .…”

Atomic/Molecular Layer Deposition for Designer's Functional Metal–Organic Materials

“…In the few additional studies involving the 4d or 5d transition metals, Nb-based films have been deposited from Nb(OEt) 5 in combination with HQ, [421] Mo-based films from molybdenum hexacarbonyl together with 1,2-ethanedithiol (EDT), [242,243] 1,4-butanedithiol, and BDT, [243] and In-based films from bis(trimethylsilyl)amidodiethylindium (INCA-1) and HQ. [369,422,423] The as-deposited In-HQ films showed a structural change upon exposure to ambient air and were found promising as flexible transparent films. [424] Tin-based hybrid Figure 9.…”

Low-temperature ALD/MLD growth of alucone and zincone thin films from non-pyrophoric precursors

“…50 The superior mechanical properties and improved electrical conductivity are some other reasons for using aromatic alcohols over the aliphatic ones; in particular, hydroquinone (HQ; benzene-1,4-diol) has been considered as a promising option. 9,[50][51][52][53][54][55] From Table 1 listing some representative reported Al-HQ and Zn-HQ processes, the dominating roles of TMA and DEZ as the metal precursor are seen.…”