Low Temperature Deposition of PNO Films by PECVD Process
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
Amorphous phosphorous-nitrogen-oxygen (PNO) coatings, prepared as described in U.S. Patent 4,172,158 by chemical vapor deposition in the temperature range of 400Œ to 900ŒC, are preferably prepared by a plasma-enhanced chemical vapor deposition (PECVD) process at temperatures below 400ŒC. The thus-produced PNO films are very stable and immune to attack by acids and acid mixtures, including hydrofluoric acid. As a consequence process repeatability is excellent with minimal reliability problems in semiconductor applications or for optical insulation in waveguide-quartz optics used in communication. The plasma-enhanced chemical vapor deposition can be achieved at pressures of one Torr or less employing phosphorous-bearing compounds, such as Ph3, P2O5, or trimethylphosphite, and NH3, O2 or N2O, etc., as examples.