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BALD Engineering News Blog

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Probably The Best ALD news blog. Covering new and old developments in Atomic Layer Deposition and Technology. From BALD Engineering:

Selective Area Spatial Atomic Layer Deposition (SALD) by Kodak

Spatial ALD Posted on 2014-02-15 22:49:47

Selective Area Spatial Atomic Layer Deposition of ZnO, Al2O3, and Aluminum-Doped ZnO Using Poly(vinyl pyrrolidone)

Carolyn R. Ellinger and Shelby F. Nelson

Chem. Mater. January 30, 2014 (Web)


Spatial atomic layer deposition (SALD) is gaining traction in the thin film electronics field because of its ability to produce quality films at a fraction of the time typically associated with ALD processes. Here, we explore the process space for the fabrication of thin film patterned-by-printing electronics using the combination of SALD and selective area patterning. First, a study of SALD growth conditions for the three primary components of our metal oxide thin film electronics, namely alumina (Al2O3) dielectric, zinc oxide (ZnO) semiconductor, and aluminum doped ZnO (AZO) conductor, provides insight into the potential trade-offs in performance, substrate latitude (temperature), and process speed. At constant precursor partial pressures, the precursor exposure times and substrate temperatures were varied from 25 to 400 ms and from 100 to 300 °C, respectively. The very short gas exposure and purge times obtainable only with a spatial implementation of ALD are shown always to be advantageous for throughput and process speed, even though growth is far from the “ideal” ALD condition of saturated monolayer growth. Using the same range of process conditions, we evaluated the ability of very thin layers of poly(vinyl pyrrolidone) (PVP) to inhibit film growth. We demonstrate that PVP sufficiently inhibits the growth of all three materials at temperatures at or above 150 °C to usefully pattern high-quality electronic devices. Additionally, we found that very thin layers of PVP are most effective at higher temperatures and fast ALD cycles. Thus, faster SALD cycles are advantageous from both throughput and patterning performance perspectives.

Using TiN ALD to create high strength low weight Nano Meta Materials

Atomic Layer Deposition (ALD) Posted on 2014-02-15 22:10:58

Fabrication and deformation of three-dimensional hollow ceramic nanostructures
Jang, Lucas R. Meza, Frank Greer, Julia R. Greer
Nature Materials, 12 (2013) 893–898, DOI:doi:10.1038/nmat3738

Left: Skeletal natural biological materials versus TiN nanolattices. Right: Compression experiments on a single unit cell.

In the analysis of complex, hierarchical structural meta-materials, it
is critical to understand the mechanical behavior at each level of hierarchy in
order to understand the bulk material response. We report the fabrication and
mechanical deformation of hierarchical hollow tube lattice structures with
features ranging from 10 nm to 100 μm,
hereby referred to as nanolattices. Titanium nitride (TiN) nanolattices were
fabricated using a combination of two-photon lithography, direct laser writing,
and atomic layer deposition. The structure was composed of a series of
tessellated regular octahedra attached at their vertices. In situ uniaxial
compression experiments performed in combination with finite element analysis
on individual unit cells revealed that the TiN was able to withstand tensile
stresses of 1.75 GPa under monotonic loading and of up to 1.7 GPa under cyclic
loading without failure. During the compression of the unit cell, the beams
bifurcated via lateral-torsional buckling, which gave rise to a hyperelastic
behavior in the load–displacement
data. During the compression of the full nanolattice, the structure collapsed
catastrophically at a high strength and modulus that agreed well with classical
cellular solid scaling laws given the low relative density of 1.36 %. We
discuss the compressive behavior and mechanical analysis of the unit cell of
these hollow TiN nanolattices in the context of finite element analysis in
combination with classical buckling laws, and the behavior of the full
structure in the context of classical scaling laws of cellular solids coupled
with enhanced nanoscale material properties.

Screendump from the video below, showing the fabrication method of the 3D architected nano meta materials described in the Nature publication above.//

Video from Solve for X – Julia Greer – 3D Architechted Nano Metamaterials at World Economic Forum.

The Julia Greer Group at Caltech:

Idea and inspiration for this post taken from the Next Big Future Blog.