Adding 3D to conventional SEM or FIB surface imaging information
In situ Surface Sensing and Nanoprofilometry for Focused Electron and Ion Beam Induced Process Verification with the new Raith NanoSense
Nanopatterning processes and corresponding parameters are typically well understood for standard nanofabrication applications using resist-based electron beam lithography (EBL) or FIB milling processes.
However, advanced and innovative nanofabrication applications involving e.g. (3D-) focused electron or ion beam induced deposition/etching processes (FEBIP/FIBIP) or complex FIB patterning tasks on new materials might require challenging and elaborate process verification and optimization – typically in time-consuming iterative cycles. This is due to the fact that the number of variable parameters for such complex processes involving e.g. new gas chemistries or ion species is virtually “infinite”. As SEM imaging only delivers 2D information, AFM or cross-sectioning techniques are typically involved in order to retrieve the required 3D information.
Efficient 3D milling profile visualization
The new Raith NanoSense - available for eLINE Plus and ionLINE - offers a far more efficient and straightforward solution, helping to qualify FEBIP/FIBIP and milling processes in situ within minutes. Nanoprofilometric scans for both additive (deposition) or subtractive (milling/etching) surface treatment yield 3D information for deposition or milling rate determination in a very efficient way – without the need for laborious unloading of the sample and ex situ AFM analysis or use of FIB-SEM technologies.
In order to achieve the expected reliable and reproducible results for 3D nanostructures, NanoSense can be implemented in both eLINE Plus and ionLINE in order to optimize and verify complex nanofabrication tasks. A standard nanomanipulator, available for both systems, can be upgraded with a surface-sensitive sensor yielding height resolutions in the order of 5nm.