On-time determination of the composition of III-V ternary layers during VPE growth

A fast automatic ellipsometer has been used for determining the composition (and the rate of growth in favorable cases) of III-V ternary compound semiconductor layers during their growth in a VPE reactor. The technique is demonstrated on Ga1−xAlxAs and GaAs1−xPx layers grown respectively in an organometallic and a chloride system. The elllipsometric angle ψ is shown to be directly related to the composition and the rate of growth of the layer. The ellipsometric angle Δ contains additional information on the growth mechanisms at the surface of the layer.