US 6,982,043 B1
Scatterometry with grating to observe resist removal rate during etch
Ramkumar Subramanian, Sunnyvale, Calif. (US); Bharath Rangarajan, Santa Clara, Calif. (US); Catherine B. Labelle, San Jose, Calif. (US); Bhanwar Singh, Morgan Hill, Calif. (US); and Christopher F. Lyons, Fremont, Calif. (US)
Assigned to Advanced Micro Devices, Inc., Sunnyvale, Calif. (US)
Filed on Mar. 05, 2003, as Appl. No. 10/382,181.
Int. Cl. B44C 1/22 (2006.01)
U.S. Cl. 216—48 28 Claims
OG exemplary drawing
 
1. A method for monitoring a patterned photoresist clad-wafer structure undergoing a first etch process comprising:
providing a wafer structure comprising a silicon substrate, one or more intermediate material layers over the substrate, and a first patterned photoresist layer overlying the one or more intermediate material layers;
irradiating at least one exposed portion of the wafer structure through at least one opening in the first patterned photoresist layer to effect an image-wise transfer from the photoresist layer to the wafer structure;
monitoring the first patterned photoresist layer during the image-wise transfer via a pattern-specific grating structure to obtain data relating to the photoresist layer; and
according to the obtained data, determining a removal rate of the first patterned photoresist layer in order to facilitate ascertaining at least one of one or more adjustments to at least a subsequent wafer clean process and a thickness of at least a second photoresist layer to be employed in at least a second etch process.