Shyam Surthi

Direct Impact of Chemical Bonding of Oxynitride on Boron Penetration and Electrical Oxide Hardening for Nanoscale Flash Memory

We report the direct correlation between chemical bonding and the physical-electrical properties of oxynitride (SiON). Through comparing oxynitrides grown by furnace anneal and by plasma method in the low-nitrogen-concentration region (<; 16 at %), we found that the boron blocking efficiency and oxide hardening against high-field electrical stress are directly enhanced by the N-Si3 and N-(SiOx)3 configurations, while the Si2-N-O configuration, in spite of the much higher nitrogen concentration, moderately degrades the hardening effect with less improvement for boron blocking. The results indicate that controlling the nitrogen bonding configuration for tunnel oxide may be a key solution to the insufficient reliability of nanoscale Flash memory.

Mechanism of Surface Bump Defect Formation in Phosphorus Doped Polysilicon-Silicon Nitride Film Stack

Formation of bump defect on the surface of silicon nitride film deposited on top of phosphorus doped amorphous silicon layer was studied. The bump defect formation was found to be caused by localized phosphorus segregation on polysilicon surface. Wet chemical treatment of silicon surface involving HF- H2O2 chemistries were found to reduce bump defect formation.

Dependence of Si/sub 3/N/sub 4/ film properties on precursor chemistry

Silicon nitride films are used as oxidation barriers, mobile ion barriers, hard masks and capacitor dielectrics in integrated circuit manufacturing. Properties of silicon nitride layers are characterized relative to physical, optical, chemical and electrical aspects that pertain to specific applications. The process integration of silicon nitride within a device structure depends upon uniformity and controllability of the deposition conditions. Precursors used in the silicon nitride deposition reaction will affect stoichiometry and reaction rates. The trisilylamine (TSA) precursor is compared to standard dichlorosilane (DCS) in terms of performance parameters