Investigation of borophosphosilicate glass roughness and planarization with the atomic force microscope technique

The ability of the atomic force microscope (AFM) technique to detect and to characterize surface roughness of as-deposited and thermally annealed boro phosphosilicate glass (BPSG) films, deposited using atmospheric and sub-atm ospheric pressure TEOS-ozone based chemical vapor deposition (CVD) as well as atmospheric and row pressure silane-based CVD, have been demonstrated. T he as-deposited BPSG films processed under atmospheric pressure conditions produced higher surface roughness than BPSG films deposited at a reduced pr essure. Thermal treatment of BPSG glass films smoothened the film surface r oughness. However, the liquid defects on the film surface were found to aff ect the accuracy of the roughness measurements. The AFM demonstrated to be a quick and non-destructive technique for the characterization of BPSG plan arization in terms of flow angle on the step model of integrated semiconduc tor circuit devices. The correlation between AFM flow angle and scanning el ectron microscopic analysis of the same device areas showed a linear depend ency for angles less than 80 degrees. (C) 1999 Elsevier Science S.A. All ri ghts reserved.