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Atomic Layer Deposition (ALD)

Atomic Layer Deposition (ALD) is a true nanotechnology, allowing ultra-thin films of a few nanometres to be deposited in a precisely controlled way. Plasma allows: unique surface pre-treatments, control of film properties and a wider variety of deposition precursors.

Highlights

  • Self-limiting atomic layer-by-layer growth
  • Highly conformal coating
  • Pin-hole and particle free deposition
  • Low plasma damage
  • Low-temperature ALD processes
  • Reduced nucleation delay
  • Wide range of materials
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ALD cycle for Al2O3 deposited using TMA and O2 plasma

Only step 3 varies between H2O for the thermal process or O2 plasma. As the ALD process deposits precisely one atomic layer in each cycle, complete control over the deposition process is obtained at the nanometre scale:

A. TMA chemisorption B. TMA purge C. O2 plasma D. Short post plasma purge

A. TMA chemisorption  |  B. TMA purge  |  C. O2 plasma  |  D. Short post plasma purge

Thermal ALD

  • Conformal coating can be achieved even in high aspect ratio and complex structures
  • A very wide variety of materials is possible with Atomic Layer Deposition, such as:
    • Oxides:
      Al2O3, HfO2, SiO2, TiO2, SrTiO3, Ta2O5, Gd2O3, ZrO2, Ga2O3, V2O5, Co3O4, ZnO, ZnO:Al, ZnO:B, In2O3:H, WO3, MoO3, Nb2O5, NiO, MgO, RuO2
    • Fluorides: MgF2, AlF3
    • Organic-hybrid materials: Alucone
    • Nitrides: TiN, TaN, Si3N4, AlN, GaN, WN, HfN, NbN, GdN, VN, ZrN
    • Metals: Pt, Ru, Pd, Ni, W
    • Sulfides: ZnS, MoS2

Remote Plasma Enhanced ALD (PEALD)

In addition to the benefits of thermal ALD, PEALD allows for a wider choice of precursor chemistry with enhanced film quality:

  • Plasma enables low-temperature ALD processes and the remote source maintains low plasma damage
  • Eliminates the need for water as a precursor, reducing purge times between ALD cycles - especially for low temperatures
  • Higher quality films through improved removal of impurities, leading to lower resistivity, higher density, etc
  • Effective metal chemistry through use of hydrogen plasma
  • Ability to control stoichiometry/phase
  • Reduced nucleation delay
  • Plasma surface treatment
  • Plasma cleaning of chamber is possible for some materials

OpAL
FlexAL
Loading Open load
Load lock or Cassette
Substrates Up to 200mm wafers & pieces directly on stage  Up to 200mm wafers handling and pieces on a carrier plate
Bubbled liquid & solid precursors Up to 4 plus water, ozone and gases Up to 8 plus water, ozone and gases
Max precursor source temperature 200ºC 200ºC
MFC controlled gas lines with rapid delivery system;  1) thermal gas precursors (e.g. NH<sub>3</sub>, O<sub>2</sub>) 2) plasma gases (e.g. O<sub>2</sub>, N<sub>2</sub>, H<sub>2</sub>) 2 internally. Up to 8 in externally mounted gas pod Up to 10 in externally mounted gas pod
Download ALD Brochure

ALD Systems