The PALS-1 is a depth-selective Positron-Annihilation Lifetime Spectroscopy (PALS) system that measures atomic-and nano-scale pores in thin film samples. The depth-selective PALS has widespread use for various materials, such as next-generation very large-scale integration materials, polymer coating films, porous films and so on. The technique, however, has only been available in large facilities with accelerators for positron production. Fuji Imvac Inc. and AIST have developed a compact PALS system that can be used in small Principle of pulse-beam based PALS system laboratories. The PALS-1 system uses an energy variable pulsed positron beam that is implanted into a sample at a selected depth, and the time interval between the incidence of positron and its annihilation with an electron is measured. The pore size can be determined from the annihilation lifetime of the positrons. Our unique techniques of high-efficiency beam production and high-compression beam pulsing enable practical measurements by using a low-activity positron source, and thereby enable the size of the system to be reduced.

Specification and Performance

  • Dimension: 3m(L) x 0.6m(D) x 1.5m(H)
  • Positron source: Na-22 (max. activity 1GBq)
  • Observation depth: Surface ~μm (selective)
  • Measurable pore size :atomic-vacancy ~10 nm
  • Measurement time :1spectrum<1hr


  • VLSI materials:
    Low-k dielectrics (porous, nonporous), High-k gate dielectrics, Cu barrier films, Electroplated Cu films SOI, Strained Si, Ion-implanted Si, Resists, ARC, etc
  • III-V, II-VI semiconductors:
    GaN, InN, ZnO, SiC, GaAs, etc
    Porous materials, Zeolite、Membranes,
    Polymer coating films etc.

Click here for available Product Brief (PDF)

Designed and developed by
Advanced Defect-Characterization Research Group, Research Institute of Instrumentation Frontier, National Institute of Advanced Industrial Science and Technology (AIST)