NanoFrazor AFM image (3D view) of a multilevel hologram written in PPA resist with NanoFrazor Explore. The image is taken during the patterning process.
In-situ Inspection & Metrology
Conventional lithography processes require wet development of the resist before the written features can be inspected and measured.
Direct-write lithography processes such as NanoFrazor lithography and low-throughput laser writing directly sublimate special resists like PPA. This direct removal of resist enables immediate inspection and metrology of the written features, which is beneficial for process development and rapid turnaround fabrication. Furthermore, it allows the NanoFrazor tools to achieve and maintain extremely high patterning quality by the patented “Closed-Loop Lithography“ approach.
The NanoFrazor systems use the same tip that is used for patterning for in-situ inspection of the written structures. Topography is imaged by means of a special AFM (atomic force microscopy) technique, which originates from the discovery of the Noble Prize winner Gerd Binnig that the electrical resistance of the IBM Millipede cantilevers was strongly distance dependent. This discovery enabled the easy-to-use and reliable NanoFrazor AFM method enabling fast imaging and accurate metrology of high-resolution shallow topographies in soft surfaces (like resist coatings).
NanoFrazor AFM image of IBM logo written 4 nm deep into PPA resist with 8 nm half-pitch resolution.
NanoFrazor AFM image of a photon sieve written into PPA by NanoFrazor Explore.
Courtesy of Adam Jeff, CERN