Spin-on-glass for 200 nm trench isolation structures

Technologies for utilizing spin-on-glass (SOG) in trench isolation are discussed. Two trench isolation technologies: a trench filled with SOG and a polysilicon filled trench planarized by SOG, are examined. The authors have successfully filled and planarized trenches as small as 200 nm without cracking or void formation using a polysiloxane SOG. Furnace, rapid thermal processing, and Si implant anneal technologies were all investigated, and all demonstrated useful results. An etchback process for the SOG planarized, polysilicon filled trench is presented. Finally, a phenomenological model for planarizing narrow width trenches is developed.