Thermal, plasma-enhanced and hot-wire assisted ALD of two- and single-element films

    Activity: Talk or presentationInvited talk


    Presented at the ASM technology seminar during the ALD-2016 conference, July 26th, 2016.

    ALD was originally developed as a purely thermal process to deposit two-element films such as oxides and nitrides. Generally, thermal processes are easier to understand, and hence control and even model, when compared to plasma-
    assisted processes. A thermal ALD process would intrinsically give a better thickness uniformity and step coverage in an industrial (batch-type) reactor.
    However, ALD of single-element films (metals and semiconductors), with a few exceptions, is difficult to realize in thermal mode. PEALD becomes a solution, however, sometimes exhibiting inferior material properties to similar films deposited with competing techniques, for instance in terms of purity
    and conduction. PEALD can have a reduced step coverage compared to thermal ALD, cause damage to the wafer under treatment by the bombardment and UV photons and involve a large variety of chemical reactions. On the other hand, the bombardment and photons can play a positive role, influencing film crystallinity and enabling low-temperature processing. Alternatively, reactive species can be generated without plasma, by collisions of molecules with a hot tungsten wire (HW) heated up to a temperature in the range of 1600-2000 oC. This process excludes the additional bombardment and illumination with photons, is highly selective and purely chemical in terms of the radical formation.
    Period6 Jul 2016
    Event title16th International Conference on Atomic Layer Deposition, ALD 2016
    Event typeConference
    Conference number16
    LocationDublin, Ireland
    Degree of RecognitionInternational