STRUCTURAL-PROPERTIES OF H-IMPLANTED INP CRYSTALS

H has been implanted in InP crystals at the energy E = 100 keV and at different doses ranging from phi = 1 x 10(13) to phi = 5 x 10(16) cm-2. The depth dependence of the elastic lattice strain has been investigated by high resolution x-ray diffractometry. The implantation produces a lattice dilation. The strain increases with increasing depth, reaches the maximum at about 0.75 mum, and then decreases rapidly; moreover the maximum strain is proportional to the dose. No extended crystal defects have been detected by transmission electron microscopy up to phi < 1 x 10(16) cm-2. At phi = 1 x 10(16) cm-2 a buried amorphous layer 28 nm in thickness has been observed at the same depth where the strain is maximum. The thickness of the amorphous layer increases by further increasing the dose and reaches a value of about 0.18 mum for phi = 5 x 10(16) cm-2.