A computerized direct liquid injection, rapid isothermal processing assisted chemical vapor deposition system for a Teflon amorphous fluoropolymer

Chemical vapor deposition (CVD) has for long been the mainstay for the deposition of critical device layers in integrated circuit technology. For the development of fast, high density, low voltage operated integrated circuits, materials with dielectric constant (K) less than that of the conventionally used SiO2 (K=3.8) are required, due to their ability to reduce signal propagation delays, power dissipation, and cross talk when used as inter level dielectrics. The copolymeric Teflon amorphous fluoropolymer (AF) is a new low K material with K=1.9. A direct liquid injection system for the CVD of Teflon AF for interlevel dielectric applications in an ultraviolet (UV) light enhanced rapid isothermal processor is reported for the first time, to the best of our knowledge. Computer interfaced electronics were designed to permit atomizing and desolvating the liquid precursor at any desired instant and interval of time. A closed loop control system monitored and regulated the substrate temperature. The films were processed with and without the UV light source. An improvement in film properties was observed when the UV source was used during processing. Our technique offers considerable advantages over other reported methods for the processing of Teflon AF. (C) 1997 American Institute of Physics.