Area-Selective Atomic Layer Deposition Using Si Precursors as Inhibitors

Abstract

Short-chain aminosilanes, namely, bis(N,Ndimethylamino)dimethylsilane (DMADMS) and (N,Ndimethylamino)trimethylsilane (DMATMS), have been used as Si precursors for atomic layer deposition (ALD) of SiO 2 . In this work, the DMADMS and DMATMS Si precursors are utilized as inhibitors for area-selective ALD (AS-ALD). The inhibitors selectively adsorb on a SiO 2 surface but not on H− Si, so that SiO 2 becomes selectively deactivated toward subsequent ALD. The deactivation of the SiO 2 surface by the inhibitors was investigated using various experimental and theoretical methods, including surface potential measurements, spectroscopic ellipsometry, and X-ray photoelectron spectroscopy. Better inhibition was observed for ALD of Ru and Pt than for ALD of Al 2 O 3 and HfO 2 . Through quantum mechanical and stochastic simulations, the difference in the blocking ability for noble metal and metal oxide ALD by the aminosilane inhibitors could be attributed to the inherently partial surface coverage by the inhibitors at their saturation and the reactivity of the subsequent ALD precursors. As silane inhibitors can be easily integrated with vacuum-based processes to facilitate high volume manufacturing of upcoming electronic devices, the current study provides a potential approach for the utilization of AS-ALD in pattern fabrication inside 3D nanostructures.

Effect of reactive gases (NH3/N2) on silicon–nitride thin films deposited with diiodosilane (SiH2I2) precursors

“…Figure 10 sets out the XRR analysis results showing the difference in thin-film density along the plasma treatment method. The density of the thin films treated with a He plasma before the deposition reaction was 3.05 g/cm 3 while the density of thin films treated after the reaction was 3.21 g/cm 3 . Although the sequence of the He plasma treatment affected the results, the treatment was verified to improve the thin-film density.…”

“…However, the 3D NAND flash memory has an even more complex structure than the existing 2D counterpart, and thin films with uniform thickness as have to be deposited even in a complex structure. To this end, a thin-film deposition method, either chemical vapor deposition (CVD) or atomic layer deposition (ALD), which has higher step coverage, is required [1][2][3]. The 3D NAND flash memory proposed in this study uses the charge-trap method instead of the existing floating-gate method.…”

Relation between Reactive Surface Sites and Precursor Choice for Area-Selective Atomic Layer Deposition Using Small Molecule Inhibitors

“… 32 Studies by Khan et al and Soethoudt et al have also shown that ALD precursors with inherent selectivity for precursor adsorption can be employed as SMI to achieve area-selective ALD. 36 , 37 …”

Area-Selective Deposition of Ruthenium by Area-Dependent Surface Diffusion

“…To date, ASD can be achieved through different approaches, many of which rely on the combined use of surface modifications and vapor phase deposition techniques such as chemical vapor deposition (CVD) [10][11][12][13] and atomic layer deposition (ALD) 4, [14][15] . Surface modifications are typically aimed at suppressing the adsorption of precursor molecules on nongrowth surfaces [16][17][18][19][20][21][22][23][24][25][26][27] . However, the growth and morphology of deposits is not dictated by adsorption alone, but is rather the result of the competition between adsorption, surface diffusion, and aggregation of adspecies [28][29][30][31] (Figure 1).…”