Atomic Layer Deposition (ALD)

ALD cycle for Al2O3 deposited using TMA and O2 plasma6. Only step 3 varies between H2O for the thermal process or O2 plasma:

1.  TMA Dose	2. TMA Purge	3. O2 Plasma	4. Short post plasma purge

ALD can be used for many applications including:

• High-k gate oxides
• Storage capacitor dielectrics
• Pinhole-free passivation layers for OLEDs and polymers
• Passivation of crystal silicon solar cells
• High aspect ratio diffusion barriers for Cu interconnects
• Adhesion layers
• Organic semiconductors
• Highly conformal coatings for microfluidic and MEMS applications
• Other nanotechnology and nano-electronic applications
• Coating of nanoporous structures
• Fuel cells, e.g. single metal coating for catalyst layers
• Bio MEMS

The benefits of remote plasma Atomic Layer Deposition

In addition to the benefits of thermal ALD, remote plasma 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
• Effective metal chemistry through use of hydrogen plasma rather than complex thermal precursors
• 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.
• Ability to control stoichiometry
• Plasma surface treatment
• Plasma cleaning of chamber is possible for some materials

ALD Tools from Oxford Instruments