PRECISION LATTICE SPACING MEASUREMENTS USING X-RAY CU K-ALPHA DOUBLET

A precision method of measuring the lattice spacing difference by a se nsitivity of 1 part in 10(7) is presented. The method uses the K alpha doublet from one conventional X-ray tube as two beams with a position sensitive proportional counter in a double-crystal spectrometer. To a chieve this sensitivity the device positioning the sample crystal para llel to the monochromator is used. The method is applied to the examin ation of the lattice spacing variations in silicon crystals containing 0.93 to 1.5 x 10(18) atoms/cm(3) of oxygen contents which are subject ed re, a two-step (low-high) annealing. The lattice spacing difference s obtained for these samples are in the range of 10(-7)-10(-6).