FlexAL II: Atomic Layer Deposition (ALD)

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Atomic Layer Deposition (ALD)
Instrument Type Deposition
Techniques Atomic Layer Deposition of
Oxides and Nitrides
Staff Manager Kelly McKenzie
Staff Email kmmckenz@caltech.edu
Staff Phone 626-395-5732
Reserve time on FBS
Request training via FBS User Dashboard
Lab Location B235 Steele
Lab Phone 626-395-1532
Manufacturer Oxford Instruments
Model FlexAL II


The Atomic Layer Deposition (ALD) system is an Oxford Instruments Plasma Technology FlexAL II platform that is designed to grow thin films one atomic layer at a time under very precise deposition conditions. It is configured with a 240 mm diameter resistance-heated, RF-biased aluminum electrode with temperature control to 600 °C, and substrate sizes up to 6 inches (150 mm), with optional configuration for 8 inches (200 mm). There is an inductively-coupled plasma (ICP) source for plasma-enhanced ALD, as well as the more traditional thermal processes, with six precursor gases to grow a variety of high-purity oxides and nitrides.

Some film examples by KNI lab members include thermally-grown conductive TiO2 as protective coatings for semiconducting photoanodes in water-splitting cells, thermal and plasma-assisted Al2O3 and HfO2 as gate dielectrics in 2D transition metal dichalcogenide materials, as well as NbN and TiN deposition.

  • Aluminum oxide and nitride deposition
  • Silicon dioxide and nitride deposition
  • Titanium oxide and nitride deposition
  • Hafnium oxide deposition
  • Niobium oxide and nitride deposition
  • Deposition of other films can be made available upon request
Allowed material in ALD System
  • Si, SixNy, SiO2, SOI
  • Hard masks compatible with process temperature
ALD Gas List (links to SDS)
ALD Precursor List (Links to SDS)


Equipment Status
SOPs & Troubleshooting
Process Documents (login to LabRunr required)
Process Resources
Manufacturer Manuals


System Features
  • FlexAL ALD Process Module
  • The chamber is electrically heated to 150 °C
  • Two ports at 70° angle from normal for ellipsometry and an additional port for analytical equipment such as RGA
  • Precursor Multi-Bubbler Cabinet 6 Way
  • Standard Gas Pod externally mounted (8 lines max)
  • 4 each Standard gasline and MFC for non-toxic gases
  • 3 each By-passed gasline and MFC for toxic gases
  • Ozone delivery system for ALD with up to 22% w/w ozone concentration
  • Chamber turbo pump Pfeiffer/Adixen ATH500M, ISO200 pipework, APC & heated backing valve kit
  • Chamber process pump Pfeiffer/Adixen A604H kit
  • FlexAL compact single wafer load lock kit
  • Load Lock dry pump kit
  • PC & 19" monitor
System Specifications
  • ICP 65 plasma source with 600 W 13.56 MHz RF Generator & AMU
  • ALD 600 °C biasable Inconel electrode
  • Heated 250 mTorr high resolution temperature compensated capacitance manometer
  • ALD 100 mm pumping pipework plus 100 mm fast APC
  • Process Acceptance criteria for thermal and plasma Al2O3 and TiO2

Related Instrumentation in the KNI

Sputtering Systems
Electron Beam Evaporation Systems
Chemical Vapor Deposition