Detector for Plasma Density Measurements in Reactive Ion Etching
Original Publication Date: 1985-Jul-01
Included in the Prior Art Database: 2005-Feb-18
Information on area uniformity in reactive ion etching process tools is crucial to process uniformity control. Test runs are made routinely; wafers coated and patterned with resist are placed in the tool and processed. Extensive microscopic evaluation follows. Upon completion of the step, product runs follow. This method is inaccurate, long and does not allow daily adjustment of the tool parameter in a simple way. A special detector plate is disclosed which allows the following: a) collection of plasma density information at the same time in different areas of the tool enceinte, and b) measurement of the vertical profile of ion densities at the same areas for proper tool adjustment. The figures illustrate the principle of the invention. The invention consists of an aluminum plate 1 about .