Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Reaction Mechanisms during Plasma-assisted Atomic Layer Deposition

Figure 1: Schematic concept of the different diagnostics implemented in situ to obtain a fundamental understanding of the reaction mechanism of plasma-assisted ALD
Figure 1: Schematic concept of the different diagnostics implemented in situ to obtain a fundamental understanding of the reaction mechanism of plasma-assisted ALD

Abstract:
Dr Erik Langereis and Prof Erwin Kessels
Department of Applied Physics, Eindhoven University of Technology, The Netherlands

Reaction Mechanisms during Plasma-assisted Atomic Layer Deposition

UK | Posted on June 14th, 2010

Atomic layer deposition (ALD) is considered the primary candidate for growth of conformal films with thickness control on the atomic level. The technique derives its growth control by alternating (two) self-limiting adsorption reactions in order to ensure that a submonolayer of film is deposited per so-called ALD cycle. By selecting the appropriate amount of deposition cycles, the film thickness can be controlled with ultimate precision.

A novel ALD concept is to use a plasma to activate one of the reactants in the gas phase in order to provide additional reactivity to the surface chemistry. These plasma-assisted ALD processes are researched to allow for deposition at reduced temperatures, to realize improved and tunable film properties, and to increase the choice in chemistry and precursors. To obtain a fundamental understanding of the surface reactions taking place and to evaluate the merits of the use of a plasma, a systematic study on the reaction mechanism of plasma-assisted ALD has been carried out for the deposition of metaloxides, metal-nitrides, and noble metals (Fig. 1).

Especially at reduced substrate temperatures, plasma-assisted ALD of metal-oxides distinguishes itself by providing good quality films due to the reactivity delivered by an O2 plasma. By determination of the surface groups by transmission infrared (IR) spectroscopy [1] and the reaction by-products by the combination of mass spectrometry and optical emission spectroscopy (OES) [2], it has been established that the Al2O3 growth is driven by a combustion-like surface chemistry. This chemistry proceeds for depositions down to room temperature. At this low temperature, it is observed that the plasma exposure time is an effective means to optimize the film quality.

For plasma-assisted ALD of metal-nitrides, the reducing power of an H2 plasma is found to be key in depositing conductive films. Using a plasma provides, moreover, the opportunity to tailor the material properties of the film by controlling the plasma condition. For example, by varying the plasma exposure time and plasma gas composition, the TaNx film properties can be controlled from conductive TaN to semiconductive Ta3N5 as evident from spectroscopic ellipsometry [3,4].

Furthermore, for ALD of noble metals such as Pt and Ru, the nucleation and film closure can be improved considerably using a plasma, which can result in smoother and thinner applicable metal films [5]. The mechanisms and growth observations deduced from these studies are expected to be generic for equivalent plasma-assisted ALD processes.

[1] Langereis et al., Appl. Phys. Lett. 92, 231904 (2008).
[2] Heil et al., J. Appl. Phys. 103, 103302 (2008).
[3] Langereis et al., J. Appl. Phys. 102, 083517 (2007).
[4] Langereis et al., topical review in J. Phys. D.: Appl. Phys. 42, 073001 (2009)
[5] Knoops et al., Electrochem. Solid-State Lett. 12, G34 (2009).

####

For more information, please click here

Copyright © Oxford Instruments

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Particle Works creates range of high performance quantum dots February 23rd, 2017

EmTech Asia breaks new barriers with potential applications of space exploration with NASA and MIT February 22nd, 2017

JPK selects compact tensile stage from Deben for their NanoWizardŽ AFM platform to broaden capabilities for materials characterisation February 22nd, 2017

Thin films

Dual-function nanorod LEDs could make multifunctional displays February 11th, 2017

NREL research pinpoints promise of polycrystalline perovskites February 8th, 2017

New material with ferroelectricity and ferromagnetism may lead to better computer memory December 21st, 2016

ANU invention to inspire new night-vision specs December 7th, 2016

Academic/Education

Nominations Invited for $250,000 Kabiller Prize in Nanoscience: Major international prize recognizes a visionary nanotechnology researcher February 20th, 2017

Oxford Nanoimaging report on how the Nanoimager, a desktop microscope delivering single molecule, super-resolution performance, is being applied at the MRC Centre for Molecular Bacteriology & Infection November 22nd, 2016

The University of Applied Sciences in Upper Austria uses Deben tensile stages as an integral part of their computed tomography research and testing facility October 18th, 2016

Enterprise In Space Partners with Sketchfab and 3D Hubs for NewSpace Education October 13th, 2016

Announcements

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Particle Works creates range of high performance quantum dots February 23rd, 2017

GLOBALFOUNDRIES Announces Availability of 45nm RF SOI to Advance 5G Mobile Communications: Optimized RF features deliver high-performance solutions for mmWave beam forming applications in 5G smartphones and base stations February 22nd, 2017

EmTech Asia breaks new barriers with potential applications of space exploration with NASA and MIT February 22nd, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project