DIRECTIONAL PLASMA CVD TECHNOLOGY FOR SUB-QUARTER-MICRON FEATURE SIZEMULTILEVEL INTERCONNECTIONS

A new plasma chemical vaper deposition (CVD) technology, which provide s outstanding film step coverage for sub-quarter-micron, high-aspect-r atio steps on ultralarge semiconductor integrated (ULSI) device surfac es, has been developed. The technology employs a bias plasma CVD depos ition system with wide-gap electrodes and reaction gases of triethoxys ilane (TRIES) and oxygen. This technology improves the step coverage o f SiO2 films by reducing the lateral ledge to less than 60% of that as sociated with conventional plasma CVD. It also improves the film quali ty of the SiO2 deposited on the step sidewalls in reducing the sidewal l etching rate to less than 50% of that of conventional films. This te chnology has been applied to an interlevel dielectric (ILD) process in conjunction with organic spin-on-glass (SOG), and the ILD parasitic c apacitance was reduced to about 70% of that in conventional plasma CVD . This technology is very promising for application to 0.2 mu m featur e size ULSI interconnections.