Precise Diameter Measurement of Contact Holes and Inspection of Resist Residuals
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
The field in future semiconductor manufacturing can be improved, if very precise and sensitive measurements and inspection tools are developed to characterize the optical lithography process, so that a go or rework decision is possible. The most difficult process in lithography is the layer with contact holes. They are the smallest dimension in lithography. The diameter of the contact hole has to be precisely measured, and the bottom of the contact hole has to be free of resist residuals. The optical measurement systems on the market suffer from thin film interferences and low resolution.