Effluent stream monitoring of an Al2O3 atomic layer deposition process using optical emission spectroscopy

The formation of Al2O3 by Atomic Layer Deposition poses new challenges to process control. Traditional process metrics have proven not to be the most reliable indicators of process performance and in some cases not responsive to process excursions. As with any batch reaction, by-products and excess reactants are natural consequences. Process quality and performance can be gauged by monitoring these "reaction leftovers" downstream of the processing chamber. This paper will describe the use of Optical Emission Spectroscopy to trend and monitor process specific, effluent stream constituents. Where traditional methodologies fail to detect process excursions, monitoring of effluent stream wavelengths has proven to be a valuable process control tool.