NEW REFLOWABLE ORGANIC SPIN-ON GLASS FOR ADVANCED INTERLEVEL DIELECTRIC PLANARIZATION

New reflowable organic spin-on glass (SOG) was developed to form plana rized multilevel interconnections for ULSIs. This SOG had superior gap -filling and planarizing characteristics compared to those of conventi onal organic SOGs. For example, using this SOG, a 0.025 mu m wide tren ch with an aspect ratio of over 10 could be perfectly filled without v oid. The surface of a three-layered interlevel dielectric structure wi th this SOG was four times smoother than that with a conventional orga nic SOG. It was found that the excellent gap-filling planarizing prope rty of this SOG was due to the low temperature reflow (100 to 200 degr ees C). The film quality was almost the same as that of an organic SOG which has been widely used and has exhibited sufficient reliability. That is, this organic SOG gives a sufficient reliability with far impr oved gap-filling and planarization. Since the relative dielectric cons tant of this SOG is as low as 3.0, this SOG is promising to improve th e operation speed of ULSI.