Gradient area-selective deposition for seamless gap-filling in 3D nanostructures through surface chemical reactivity control

Abstract

The integration of bottom-up fabrication techniques and top-down methods can overcome current limits in nanofabrication. For such integration, we propose a gradient area-selective deposition using atomic layer deposition to overcome the inherent limitation of 3D nanofabrication and demonstrate the applicability of the proposed method toward large-scale production of materials. Cp(CH3)5Ti(OMe)3 is used as a molecular surface inhibitor to prevent the growth of TiO2 film in the next atomic layer deposition process. Cp(CH3)5Ti(OMe)3 adsorption was controlled gradually in a 3D nanoscale hole to achieve gradient TiO2 growth. This resulted in the formation of perfectly seamless TiO2 films with a high-aspect-ratio hole structure. The experimental results were consistent with theoretical calculations based on density functional theory, Monte Carlo simulation, and the Johnson-Mehl-Avrami-Kolmogorov model. Since the gradient area-selective deposition TiO2 film formation is based on the fundamentals of molecular chemical and physical behaviours, this approach can be applied to other material systems in atomic layer deposition.

Area-Selective Deposition of Ruthenium Using Homometallic Precursor Inhibitor

“…This suggests that the coverage of Ru(EtCp) 2 increases with the exposure time, leading to an improvement in the blocking property. This is consistent with our recent study 18 on the TiO 2 ASD process using a Ti PI. The areal coverage of the PI on the surface rapidly increases with PI impingement.…”

“…17 Typically, inhibitors are used for selective adsorption on different surfaces, defining growth and non-growth surfaces, to control ALD film growth on the desired surface. In our recent approach, 18 however, we discovered that selective growth can also be achieved based on different geometries, even on the same surface, to control ALD growth in 3D structures. Cp(CH 3 ) 5 Ti(OMe) 3 , a TiO 2 precursor, has been used as an inhibitor in TiO 2 ASD.…”

Atomic layer deposition in advanced display technologies: from photoluminescence to encapsulation

“…As mentioned above, ALD has been applied to the modification of QD-based devices across different scales; thus, multi-scale research and manufacturing methods are urgently required [77]. Thus, as presented in figure 6, first-principles calculations, nucleation dynamics [78], Knudsen flow dynamics, and computational fluid dynamics can be combined to achieve multi-scale simulations. The first-principles method provides the electronic and thermodynamic properties during the ALD reaction on the nanoscale.…”

Selection Criteria for Small-Molecule Inhibitors in Area-Selective Atomic Layer Deposition: Fundamental Surface Chemistry Considerations

“…For example, area-selective deposition (ASD) can be put into use to aid top-down fabrication in fully self-aligned vias. 7,8 Other application examples include ASD on photoresist, contact over gate structure, bottom-up filling, 9 selective hard-mask and etch-stop layer depositions, which have been discussed in detail by G. N. Parsons and R. D. Clark in a recent review on ASD. 5 Many of the methods described for atomically precise manufacturing rely heavily on atomic layer deposition (ALD) as a key processing step.…”

“…With the ever-shrinking dimensions of the features employed, for example, in semiconductor manufacturing, complications for such iterative processes start to arise, and complementary bottom-up methods are developed to circumvent these issues and/or expand the processing window. For example, area-selective deposition (ASD) can be put into use to aid top-down fabrication in fully self-aligned vias. , Other application examples include ASD on photoresist, contact over gate structure, bottom-up filling, selective hard-mask and etch-stop layer depositions, which have been discussed in detail by G. N. Parsons and R. D. Clark in a recent review on ASD …”