abstract |
A process for very low deposition rate plasma-enhanced chemical vapor deposition (PECVD) of nitride is provided. A nitride layer is used, for example, as a precursor for nitride spacers formed on the sidewalls of a polysilicon gate. The nitride layer may be produced in a PECVD chamber, using an increased flow rate of nitrogen applied to the chamber, an increased flow rate of molecular nitrogen, and a reduced flow rate of ammonia. The RF power is reduced, as well as the reactor pressure. This produces a nitride layer that exhibits improvements in density, refractive index, step coverage, and thickness non-unformity within a wafer and from wafer-to-wafer. |