Planarization processes and applications - II. B2O3/P2O5 doped GeO2-SiO2 classes

Plasma enhanced chemical vapor deposition of boron and phosphorus eloped mi xed GeO2-SiO2 glass films in a horizontal tube reactor using germane (GeH4) , silane (B2H6), diborane (PH3), phosphine (PH3), and oxygen (O-2) has been studied. The glass films offer the potential for both trench refilling and interlevel dielectric applications. Film synthesis was carried out at 200 degrees C using a dual coil inductively coupled plasma system. Oxide film c omposition was determined using energy dispersive X-ray spectroscopy and An ger energy spectroscopy. Cross-sectional scanning electron microscopy was e mployed for studing the compositional dependency of. the reflow behavior of the mixed GeO2-SiO2, P2O5-GeO2-SiO2, B2O3-GeO2-SiO2, and P2O5-B2O3-GeO2-Si O2 glass films over silicon trenches under various ambient atmospheres. Ref low experiment?, were performed at temperatures ranging from 550 to 800 deg rees C in various gas ambient atmospheres. As result of the work, a low tem perature (similar to 600 degrees C) reflow process was developed resulting in fully planar dielectric films. This process may have application tor pla narization of interlevel dielectrics for ultralarge scale integrated circui ts. (C) 1999 The Electrochemical Society. S0013-4651(99)05-027-2. All right s reserved.