Investigation of lattice deformation in proton bombarded GaP and ZnSiP2 by means of the proton-induced kossel effect

Kossel interferences of the PK_α radiation, induced by 1 MeV protons, have been used to determine “in situ” the lattice expansion of GaP and ZnSiP₂ in dependence on the proton dose.     

Solid State Analysis with the New Leipzig High-Energy Ion Nanoprobe

 The high-energy ion nanoprobe LIPSION at the University of Leipzig has been operational since October 1998. The ultrastable single ended 3.5 MV SINLETRON^TM accelerator supplies the H⁺ or He⁺ ion beam. A magnetic scanning system moves the focused beam across the sample. At present, a resolution of 150 nm in the low current mode and 300 nm at 5 pA could be achieved. The UHV grade experimental chamber is equipped with electron-, energy dispersive X-ray-, and particle detectors. They can be used simultaneously to analyse the sample by means of PIXE (particle induced X-ray emission), RBS (Rutherford backscattering) and in the case of thin samples STIM (scanning transmission ion microscopy). A goniometer allows the application of channeling measurements in single crystals in combination with these methods. The detection limits depend on the elements to be analysed and range from (1000⋯1) μg/g relative and (1⋯0.01) pg absolute. The analysis is nondestructive, but the sample has to be vacuum resistant. Applications of the nanoprobe in the field of semiconductor research, biomedicine, and archaeology will be described.     

InGaAsP quaternary layers on InP (100) substrate analysed by ion backscattering and channeling

In_1−xGa_xAs_yP_1−y layers LPE grown on InP(001) substrates are analysed by the Rutherford backscattering and channeling techniques. In addition to the layer thicknesses the compositions are determined from the random spectra and compared with the PL and XRD results. The high dechanneling rate of the He⁺ ions for [100] incidence is attributed to the displaced atoms in the distorted crystal lattice of these otherwise high-quality epitaxial layers. We find a characteristic value of Δ_χdist(0.1) = 2.3 ± 0.3% which must be taken into account for estimations of crystalline quality.