Showing posts with label in-situ metrology. Show all posts
Showing posts with label in-situ metrology. Show all posts

Thursday, August 2, 2018

Overview of In situ Studies of ALD Processes & Reaction Mechanisms

Roger Bosch and Prof. Kessels from TU Eindhoven just recently published a fantastic blog post on Atomic Limits covering the Tutorial “In situ Studies of ALD Processes & Reaction Mechanisms” that Prof. Kessels presented at the recent ALD 2018 Conference Incheon, South Korea (July 29 – August 1, 2018.

Please follow these links and enlighten your self on the follwoing topics:

Thursday, October 19, 2017

Conductance measurements optimize atomic layer deposition automatically

As reported by An in situ measurement technique that can monitor the process of atomic layer deposition (ALD) in real time has been developed by scientists in Germany. The researchers used changes in the conductance of layers over multiple ALD cycles to identify the different growth phases as they occurred, allowing undesired modes of deposition to be averted. The conductance signal was also used as the input to a genetic algorithm that could optimize the growth rate semi-automatically.

Thursday, July 13, 2017

Film Sense and Kurt J. Lesker: in-situ Ellipsometry with the FS-1

The Film Sense vision “to create easy-to-use and affordable ellipsometers” is especially relevant for in-situ applications. The Film Sense FS-1 realizes this vision by providing the power of Multi-Wavelength Ellipsometry, at an affordable price and compact size that is ideal for in-situ measurements. The FS-1 can provide real time thickness data with exceptional precision, which can be indispensable for the efficient development of new ALD processes. In the plot below, the “steps” in the data are direct observations of the thickness changes on the sample throughout the ALD cycles: the thickness increases and saturates as the precursor is introduced (trimethyl aluminum in this case), and then decreases as the film is oxidized (thermally by H2O in this case). 

The relationship between Film Sense and Kurt J. Lesker dates back to almost the inception of Film Sense.  In fact, the first Film Sense FS-1 in-situ testing was performed on a Kurt J. Lesker ALD150LX reactor in 2014.  The FS-1 has since been integrated on multiple Lesker ALD reactors, and has been used to characterize a wide variety of thin films including:  Al2O3, TiO2, HfO2, and TiN.

The ALD150LX was designed from the ground up for advanced R&D and features remote plasma as well as in-situ ellipsometry as a primary means of real time process monitoring and control during ALD.  Patented Precursor Focusing TechnologyTM (PFTTM) prevents unwanted film deposition on sensitive surfaces inside the reactor including the analytical port windows used for light transmission during in-situ ellipsometry.  The layout of the plasma-enhanced ALD (PEALD) reactor makes installation and operation of the compact FS-1 unit simple and easy. 

According to Bruce Rayner, Principal Scientist – ALD at the Kurt J. Lesker Company, “The FS-1 provides excellent performance at a very attractive price, and its robust, compact design is ideally suited for in-situ ALD applications.”

If you are coming to ALD2017 in Denver, please visit the Lesker booth #31 to see a live demonstration of the FS-1 integrated on an ALD150LX reactor.  At the Film Sense booth #1, an FS-XY150 automated mapping stage will be on display.

The Film Sense FS-1 ellipsometer is now available as an option for the Lesker ALD150LX reactor.  For more information please contact Dan Hadwiger ( or Noel O’Toole (mailto:, or visit our websites at and

Friday, July 7, 2017

Film Sense and Beneq Demonstrate in situ Multi-Wavelength Ellipsometry

Film Sense LLC and Beneq Oy have successfully installed and tested the Film Sense FS-1 Multi-Wavelength Ellipsometer system on a Beneq TFS 200 ALD reactor. According to Pasi Meriläinen, Head of Equipment and Projects, Thin Film Equipment at Beneq, “the FS-1 exceeded our expectations for ease of installation, operation, and performance”. The FS-1 brings the power of in situ Multi-Wavelength ellipsometry to ALD at a very affordable price.

The FS-1 ellipsometer can provide in situ, real time thickness data during the ALD process, with sub-nanometer thickness resolution. The in situ FS-1 data plotted below was acquired on a Beneq TFS 200 ALD reactor, and confirms the linear deposition rate of the Al2O3 film. Real time thickness information is important for verifying the performance of existing ALD processes, and can significantly reduce the development time when exploring new ALD processes and precursor materials. The in situ FS-1 data is especially valuable for characterizing the initial stages of growth, and can directly observe incubation time and other non-ideal ALD growth mode effects.

The Film Sense FS-1 ellipsometer is an option for the Beneq TFS 200 ALD reactor. For more information about the Film Sense FS-1 ellipsometer please contact Dan Hadwiger ( or visit our website LINK
To learn more about Beneq TFS 200 contact or visit the Beneq website LINK .

Wednesday, May 25, 2016

In situ metrology to characterize water vapor delivery during ALD [Open Source]

In situ metrology to characterize water vapor delivery during atomic layer deposition

Tariq Ahmido, William A. Kimes, Brent A. Sperling, Joseph T. Hodges and James E. Maslar
J. Vac. Sci. Technol. A 34, 031512 (2016) | Read More
Water is often employed as the oxygen source in metal oxide atomic layer deposition(ALD) processes. It has been reported that variations in the amount of water delivered during metal oxide ALD can impact the oxide film properties. Hence, one contribution to optimizing metal oxide ALD processes would be to identify methods to better control water dose. The development of rapid, quantitative techniques for in situwater vapormeasurements during ALD processes would be beneficial to achieve this goal. In this report, the performance of an in situ tunable diode laser absorption spectroscopy (TDLAS) scheme for performing rapid, quantitative water partial pressure measurements in a representative quarter-inch ALD delivery line is described. This implementation of TDLAS, which utilizes a near-infrared distributed-feedback diode laser and wavelength modulation spectroscopy, provides measurements of water partial pressure on a timescale comparable to or shorter than the timescale of the gas dynamics in typical ALD systems. Depending on the degree of signal averaging, this TDLAS system was capable of measuring the water partial pressure with a detection limit in the range of ∼0.80 to ∼0.08 Pa. The utility of this TDLAS scheme was demonstrated by using it to identify characteristics of a representative water delivery system that otherwise would have been difficult to predict. Those characteristics include (1) the magnitude and time dependence of the pressure transient that can occur during water injection, and (2) the dependence of the steady-state water partial pressure on the carrier gas flow rate and the setting of the water ampoule flow restriction.

Wednesday, June 10, 2015

Researchers at Rice University make ultrasensitive conductivity measurements

Here is a very interesting report that might indeed be interesting to characterize ALD growth in-situ ultra fast at optical frequencies!

(Nanowerk News) Researchers at Rice University have discovered a new way to make ultrasensitive conductivity measurements at optical frequencies on high-speed nanoscale electronic components.The research at Rice's Laboratory for Nanophotonics (LANP) is described online in a new study in the American Chemical Society's journal ACS Nano ("Charge Transfer Plasmons: Optical Frequency Conductances and Tunable Infrared Resonances"). In a series of experiments, LANP researchers linked pairs of puck-shaped metal nanodisks with metallic nanowires and showed how the flow of current at optical frequencies through the nanowires produced "charge transfer plasmons" with unique optical signatures.

Linked pairs of nanodisks as seen with a scanning electron microscope. (Image: Fangfang Wen/Rice University)

Saturday, May 16, 2015

Atomic Layer Deposition of Al2O3 on NF3-pre-treated graphene

Another great publication from ALD Lab Dresden, TU Dresden, Germany, and Marcel Junige and their and scientists at Linköping University of Technology, Sweden, using high resolution in-situ ellipsometer. This time these guys have grown Al2O3 on Graphene, which is very difficult unless you activate the inert grapheme surface. Marcel did this by a NF3 pre-treatment. The work was presented at SPIE micro technologies 2015 in Barcelona.

Atomic Layer Deposition of Al2O3 on NF3-pre-treated graphene

Marcel Junige, Tim Oddoy, Rositsa Yakimova, Vanya Darakchieva, Christian Wenger, Grzegorz Lupina, Matthias Albert, Johann W. Bartha
Conference: SPIE microtechnologies 2015 : Nanotechnology VII, At Barcelona, Spain, Volume: 9519

Optical Al2O3 layer thickness in progression over the ALD process time as observed by in-situ real-time Spectroscopic Ellipsometry, comparing the ALD of Al2O3 starting on a 100 nm thermally grown SiO2 reference versus an exfoliated graphene monolayer after 180 s NF3-pre-treatment.

Graphene has been considered for a variety of applications including novel nanoelectronics device concepts such as the recently reported Graphene Base Transistor (GBT). However, the deposition of ultra-thin films on top of graphene is still challenging: On the one hand, the deposition process must not damage or alter the pristine graphene monolayer; on the other hand, the finally deposited films have to provide appropriate functional properties regarding a specific application. In case of the GBT, a dielectric coating is desired which is both pin-hole free to prevent any short circuits and still thin enough (around 3-5 nm) to enable hot electron tunneling. Hence, the dielectric film closure on graphene needs to occur at an early stage of the deposition process. Atomic Layer Deposition (ALD) has been established as a physicochemical coating technique with excellent thickness control as well as unique conformality over complex three-dimensional-shaped substrates for the last decade. Especially the ALD of oxides has been extensively researched. Accordingly, an ALD process for Al2O3 yet exists that alternates the exposure of trimethylaluminum (TMA) and water (H2O) as the organometallic precursor and co-reactant of two corresponding self-terminating surface reactions, respectively. However, the ALD of Al2O3 has been reported to barely initiate on pristine graphene due to graphene’s lack of dangling bonds. A fluorine functionalization, using XeF2, has been found to provide additional nucleation sites resulting in conformal films without pinholes. Based on this literature finding, we studied the impact of pre-treatments by nitrogen trifluoride (NF3) on exfoliated as well as epitaxial graphene monolayers prior to the ALD of Al2O3. All experiments were conducted in vacuo; i. e. the pristine graphene samples were exposed to NF3 for 180 s in the same reactor immediately before applying 30 ALD cycles and the samples were transferred between the reactor and a surface analysis unit under high vacuum conditions. The ALD growth initiation was observed by in-situ real-time Spectroscopic Ellipsometry (irtSE) with a sampling rate of 1 Hz. The chemical surface composition before and after the ALD as well as the presence of graphene after the coating procedure were revealed by in-vacuo X-ray Photoelectron Spectroscopy (XPS). The morphology of the films was determined by Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). The defect status was examined by Raman Spectroscopy before and after the coating procedure. Atomic Layer Deposition of Al2O3 on NF3-pre-treated graphene. Available from: [accessed May 16, 2015].

Tuesday, May 12, 2015

Ultra fast real-time monitoring of ALD by Ellipsometry with 1.25 Hz sampling rate

Here is a really cool paper from Marcel Junige and his co-workers at TU Dresden IHM and collaborators showing high resolution of the half reactions in ALD and real good sampling rate. Even the fastest of them all the half reaction of TMA is sampled in-situ showing the a bunch of sampling points from the steep saturation curve. Woah - only ALD Lab Dresden can pull of a thing like this!

You can connect with Marcel on Research Gate and get a free copy!
Marcel Junige, Varun Sharma, Ralf Tanner, Daniel Schmidt, Greg Pribil, Matthias Albert, Mathias Schubert, Johann W. Bartha
2015 International Conference on Frontiers of Characterization and Metrology for Nanoelectronics (FCMN), Dresden, Germany; 04/2015