QUANTITATIVE DESORPTION ANALYSIS OF ULTRA LARGE-SCALE INTEGRATION MATERIALS BY THERMAL-DESORPTION SPECTROSCOPY

A quantitative method to evaluate desorbed gasses from ULSI materials has been investigated by thermal desorption spectrometry using a quadr upole mass spectrometer. Thermal desorption studies for hydrogen ion i mplanted Si wafers exhibited good reproducibility of measurements. The reproducibility of the H-2 desorption peak area in the thermal desorp tion spectra was found to be within 5% of relative standard deviation between measurements for the 5X10(14) H-2/cm(2) sample. Also a good ca libration curve was established between the peak area and the amount o f implanted hydrogen, ranging from 10(15) to 10(16)/cm(2). The quantit ative analysis of H-2 desorption revealed that HF treated Si(0 0 1) su rfaces were almost perfectly terminated by hydrogen. It was also confi rmed from desorption analysis of ULSI materials that inorganic desorbe d species can be quantitatively evaluated by using the calibration cur ve and by taking into account of fragmentation factor, ionization prob ability and transmission factor in mass spectrometry, and pumping spee d for the desorbed gasses. The detection limit was approximately 1X10( 13)/cm(2), even for H-2 and H2O. This work demonstrated a successful a pplication of thermal desorption spectroscopy to quantitative analysis of species in the range of 10(13)similar to 10(17)/cm(2) from ULSI ma terials.