Challenges

Etching is performed after the transfer of images through photoresist patterning, and creates the permanent features of the device. As device designs increase in complexity with different trim and double patterning schemes being added to the process flow, the demands on the etch processes are heightened, leaving little tolerance to error.

Process monitoring and control in etch require precise measurement of full feature profiles, including: CD, side wall angle, etch depth, fine profile features such as foot, notch, undercuts, high aspect ratio structures, and new material characteristics.

Solution

Nova’s scatterometry-based metrology solutions enable full CD and shape profiling measurements that include top, middle and bottom CD, sidewall angles, foot, notch and undercut, and other fine feature parameters. High accuracy and fleet matching coupled with high throughput of up to 150 WPH, make Nova’s metrology an Advanced Process Control (APC) enabler for wafer patterning. 

Nova provides a full metrology solution for wafer patterning process monitoring and control by offering integrated metrology on the track system or on the etcher for Closed Loop Control and high-sampling APC. For lot-to-lot process monitoring and control, stand-alone metrology meets the most stringent requirements.