Method of Determining Critical Thickness of Silicon Nitride Layers
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-27
The completeness and with it the critical thickness of CVD (Chemical Vapor Deposition) silicon nitride (Si3N4) layers is determined by measuring the breakdown voltage. The nucleation and growth of a CVD silicon nitride layer is a statistical process. Influential on the growth are the substrate, the gas composition in the reaction tube and the process parameters, such as the deposition rate, the temperature and whether or not LPCVD (Low- Pressure Chemical Vapor Deposition) or PECVD (Plasma-Enhanced Chemical Vapor Deposition) is used. At the start of the growth cycle, stable nuclei are generated on the substrate consisting, for example, of SiO2 . These nuclei are statistically distributed on the substrate surface. As deposition continues, the nuclei grow into islands.