Patent Number: 6,486,675

Title: In-situ method for measuring the endpoint of a resist recess etch process

Abstract: An in-situ method for measuring the endpoint of a resist recess etchprocess for DRAM trench cell capacitors to determine the buried platedepth on a semiconductor wafer thereof, including: placing an IR device onthe etch chamber; illuminating the surface of a semiconductor wafer duringetching to a resist recess depth with IR radiation from the IR device;detecting reflection spectra from the illuminated surface of thesemiconductor wafer with an IR detector; performing a frequency analysisof the reflection spectra and providing a corresponding plurality of wavenumbers in response thereto; and utilizing calculating device coupled tothe IR detector to calculate the resist recess depth at the illuminatedportion of the wafer from the plurality of wave numbers corresponding tothe reflection spectra.

Inventors: Jaiprakash; Venkatachalam C. (Beacon, NY), Mantz; Ulrich (Dresden, DE)


International Classification: G01B 11/06 (20060101); G01R 031/11 ()

Expiration Date: 11/22015