Journal of the Electrochemical Society, Vol.146, No.8, 3039-3051, 1999
Growth kinetics and deposition-related properties of subatmospheric pressure chemical vapor deposited borophosphosilicate glass film
Growth kinetics of borophosphosilicate glass (BPSG) films prepared by the chemical reaction of tetraethylorthosilicate (TEOS), triethylborate, and triethylphosphate, with ozone-oxygen mixture has been studied using a single-wafer deposition chamber at 373-458 degrees C under reduced pressure or subatmospheric pressure condition (SABPSG). Based on the comparison of the effective reaction rate constants and other kinetic features, the similarity of BPSG deposition kinetic for different types of precursors and deposition conditions are shown. Fourier transform infrared spectroscopy, X-ray fluorescence analysis, secondary ion mass spectrometry, stress measurement, optical microscopy, scanning electron microscopy, atomic force microscopy, surface laser scanning, capacitance-voltage, current voltage, and surface charge analysis techniques have been used for the characterization of SABPSG film properties. Moisture absorption and surface defect formation phenomena have been studied for both as-deposited and furnace annealed films with boron and phosphorus ranging from 3 to 6 wt %. The liquid state, solid state, and crystalline BPSG surface defects have been characterized and their relationships have been shown. A multipath and multistep reaction mechanism scheme of TEOS-ozone BPSG deposition process with the formation of active intermediate products; a scheme of porous TEOS-ozone BPSG film with embedded dopant-rich clusters, and a scheme of defect formation and growth on BPSG films are discussed. Empirical equations of quantitatively optimized BPSG dopant concentration range are presented by taking into account flow properties, defect formation, and moisture absorption processes in the film.