  We have used x-ray anomalous diffraction to extract the x-ray structure
factor of InAs quantum stick-like islands, embedded in InP. The average height
of the quantum sticks (QSs), as deduced from the width of the structure factor
profile is 2.54nm. The InAs out of plane deformation, relative to InP, is equal
to 6.1%. Diffraction Anomalous Fine Structure provides a clear evidence of pure
InAs QSs. Finite Difference Method calculations reproduce well the diffraction
data, and give the strain along the growth direction. Chemical mixing at
interfaces is at most of 1ML
