Facile patterning of functional materials via gas-phase 3D printing

TL;DR

This paper introduces a novel 3D printing method using gas-phase SALD with custom 3D printed heads for precise, selective, and high-resolution deposition of functional materials in open air.

Contribution

It demonstrates the design and fabrication of customizable SALD heads via 3D printing, enabling spatially controlled, multimaterial, and nanometric resolution deposition.

Findings

3D printed SALD heads allow for flexible patterning and material deposition.

Polymeric heads are cost-effective and disposable for rapid prototyping.

Nanometric resolution in Z-axis achieved with miniaturized circular gas channels.

Abstract

Spatial Atomic Layer Deposition (SALD) is a recent approach that is up to two orders of magnitude faster than conventional ALD, and that can be performed at atmospheric pressure and even in the open air. Previous works have exploited these assets to focus on the possibility of high-rate, large-area deposition for scaling up into mass production. Conversely, here we show that SALD indeed represents an ideal platform for the selective deposition of functional materials by proper design and miniaturization of SALD close-proximity heads. In particular, we have used the potential offered by 3D printing to fabricate custom close-proximity SALD injection heads. By using 3D printing, the heads can be easily designed and readily modified to obtain different deposition areas, free-form patterns, and even complex multimaterial structures. The heads can be printed in different materials to adjust to the chemistry of the precursors and the deposition conditions used. Polymeric heads can be used as cheap (even disposable) heads that are both used for performing deposition and for prototyping and optimization purposes. Finally, by designing a miniaturized head with circular concentric gas channels, 3D printing of functional materials can be performed with nanometric resolution in Z. This constitutes a new 3D printing approach based on gaseous precursors. Because the selective deposition strategies presented here are based on the SALD process, conformal and continuous thin films of functional materials can be printed at low temperatures and with high deposition rate in the open air. Our approach represents a new versatile way of printing functional materials and devices with spatial and topological control, thus extending the potential of SALD and ALD in general, and opening a new avenue in the field of area-selective deposition of functional materials.