DB FIB For In‐Line Process Control

Cross‐sectional analysis is an important tool for structural learning in the IC industry. FEI CLM‐3D DualBeam™ system enables IC companies to rapidly collect step‐to‐step integration information within the FAB. Both 2‐ and 3‐dimensional structures can be analyzed. Gate structures are a good example of a 2‐D structure in which the DB FIB system can provide width, thickness, sidewall angle, as well as bottom profile. In addition, it can provide qualitative information regarding the material stack, such as the step coverage of the oxide layer over the gate silicon.Deep trench hard mask layers provide an excellent illustration of a 3‐D structure in which extremely high aspect ratio elliptical trenches must be precisely cross‐sectioned to reveal accurate geometric information. The DB FIB system can precisely cross‐section these features to obtain the necessary precision‐to‐tolerance ratios. Moreover, the tool’s versatility has allowed its utilization for many other 2‐D and 3‐D structures besides gate and deep ...