| abstract |
In a method for forming an interlayer dielectric (ILD) coating on microcircuit interconnect lines of a substrate, a SiON layer is formed by using plasma-enhanced chemical vapor deposition. The deposition using a plasma formed of nitrogen, nitrous oxide, and silane gases, with the gases being dispensed at regulated flow rates and being energized by a radio frequency power source. The plasma reacts to form SiON which is deposited on a semiconductor substrate. During processing the deposition temperature is reduced to under 400 degrees Celsius, specifically temperatures in the range of about 350 degrees Celsius to about 380 degrees, Celsius, resulting in a substantially reduced incidence of stress-induced voiding in the underlying interconnect lines. Additionally, during deposition, minor adjustments are made to deposition temperature and process pressure to control the optical characteristics of the SiON layer. The SiON layer is tested for acceptable optical properties and acceptable SiON layers are coated with a SiO 2 layer to complete formation of the ILD. Once the ILD is formed the substrate is in readiness for further processing. |