JPH0449904B

In a method for predicting a density of micro crystal defects to be generated in a semiconductor element, an infrared absorption spectrum associated with a silicon wafer (30), which is used for the manufacture of the semiconductor element, is formed by a spectrum forming system (10, 18, 22, 34). The spectrum has a first oxygen absorption peak at the wavenumber range of 1150 to 1050 cm and a second oxygen absorption peak at 530 to 500 cm . First and second coefficients indicating oxygen concentrations at the first and second peaks are read by a reading unit (12). The density of the micro crystal defects are predicted by using a ratio of the first and second coefficients as a monitor.