CHARACTERIZATION OF LATTICE SPACING AND INCLINATION AROUND CELLS IN LIQUID-ENCAPSULATED CZOCHRALSKI GAAS CRYSTALS USING A 100X100 MU-M(2) INCIDENT X-RAY-BEAM

Lattice spacing and inclination around cells were investigated precise ly fur both undoped high etch-pit-densities (EPD) liquid-encapsulated Czochralski (LEG) GaAs crystal of the order of 10(4) cm(-2) and undope d As-ambient LEC (As-LEG) crystal of low EPD of the order of 10(3) cm( -2). Measurement of the lattice spacing and the inclination was carrie d out by the triple crystal method using a 100X100 mu m(2) size incide nt beam of high-intensity synchrotron radiation, It was revealed that the lattice spacing varied by almost Delta d, on the order of 10(-4) A ngstrom, due to the cellular structure of the high EPD crystal. In add ition, the low EPD GaAs crystal grown by the As-LEG method showed cons iderably less variation in lattice spacing and inclination than the hi gh EPD LEC GaAs crystal. (C) 1996 American Institute of Physics.