Area-Selective Atomic Layer Deposition of SiO₂ Using Acetylacetone as a Chemoselective Inhibitor in an ABC-Type Cycle

Abstract

Area-selective atomic layer deposition (ALD) is rapidly gaining interest because of its potential application in self-aligned fabrication schemes for next-generation nanoelectronics. Here, we introduce an approach for area-selective ALD that relies on the use of chemoselective inhibitor molecules in a three-step (ABC-type) ALD cycle. A process for area-selective ALD of SiO2 was developed comprising acetylacetone inhibitor (step A), bis(diethylamino)silane precursor (step B), and O2 plasma reactant (step C) pulses. Our results show that this process allows for selective deposition of SiO2 on GeO2, SiNx, SiO2, and WO3, in the presence of Al2O3, TiO2, and HfO2 surfaces. In situ Fourier transform infrared spectroscopy experiments and density functional theory calculations underline that the selectivity of the approach stems from the chemoselective adsorption of the inhibitor. The selectivity between different oxide starting surfaces and the compatibility with plasma-assisted or ozone-based ALD are distinct features of this approach. Furthermore, the approach offers the opportunity of tuning the substrate-selectivity by proper selection of inhibitor molecules.

Isotropic Atomic Layer Etching of ZnO Using Acetylacetone and O2 Plasma

“…The absence of SiO 2 etching can be explained by density functional theory simulations that we performed for the chemisorption reaction of Hacac on SiO 2 . 42 On this surface, the Hacac chemisorption was found to be thermodynamically unfavorable; therefore, SiO 2 etching was not expected. The etching of HfO 2 , on which Hacac does adsorb, 42 would require the formation of Hf(acac) 4 , which we believe is unlikely on a surface because of steric reasons.…”

“…This apparent thickness increase can be attributed to the adsorption of Hacac molecules onto the ZnO surface, similarly to what has been observed on Al 2 O 3 substrates for the ABC-type area-selective ALD of SiO 2 . 42 The subsequent thickness decrease might be due to partial decomposition of acac species on the ZnO surface as will be discussed below. Note that the measured thickness does not decrease below the starting ZnO thickness during sequence 1.…”

Electrochemical Atomic Layer Deposition (EC-ALD) Low Cost Synthesis of Engineered Materials a Short Review

“…This platform offered new possibilities to current additive nano manufacturing tools with the potential to fabricate one sheet after the other by using multi-electrode arrays. The flexibility and low-cost of the fabrication method could be used for generating novel devices, particularly in the domain of photonics and energy conversion [44].…”

Spontaneous selective deposition of iron oxide nanoparticles on graphite as model catalysts

“…[19][20][21][22][23] The focus for next-generation heterogeneous catalysts is on rational design, where metal and metal oxide materials could be selectively grown in dened areas to control the placement and concentration of catalyst materials, while minimizing costs. [24][25][26][27] For selective deposition by area activation, the selectivity greatly depends upon the interaction between the metal adsorbate and the surface sites. 24,27 Carbon supports are typically utilized due to their high thermal and mechanical stability, without surface metal support interactions.…”