Nanofabrication

The goal of nanopatterning research at the Center for Nanoscale Materials (CNM) is to provide nanofabrication support to all CNM scientific groups and to develop new nanofabrication techniques. When the CNM is in full operation, the tool set will include state-of-the-art electron beam nanopatterning, focused ion beam nanopatterning, nanoimprint, optical lithography, and advanced pattern transfer and thin-film deposition and synthesis capabilities. In addition, there will be clean room laboratories dedicated to metrology, electrochemistry, wet etching, and biosynthesis. The CNM staff is dedicated to pushing the limits of current state-of-the-art methods to reach the 10-nm regime, combine self-assembly with lithographic patterning, and aid and train users in incorporating modern nanofabrication techniques into their nanoscience research.

Nanoscale SiO2 windows fabricated using electron-beam lithography (EBL) and reactive ion etching (RIE). Precise control over the size and position of holes offers a unique way to create high-density homogenous arrays of ultra-small windows for selective area epitaxial regrowth (left), Planar magnetic cobalt nano-contacts fabricated by e-beam lithography. The outreaching gold contact pads allow for electrical transport characterization of the nano-contacts (right).

Electron beam (e-beam) lithography is the most important lithographic technique used for high-resolution patterning. Many other nanolithographic techniques depend upon e-beam lithography because they require masks or templates to transfer the pattern onto the work substrate. Argonne currently operates both the 30-kV Raith 150 and the 100-kV JEOL 9300F e-beam lithography tools in the CNM.

	Microlithography cleanroom equipment: Karl Suss MA-6 UV double-sided contact mask aligner (left) and Raith 150 e-beam facility — view of column, exposure chamber, and loadlock for sample loading (above).

Activities

• High- and low-voltage electron beam lithography
• Optical lithography
• Nanoimprint and soft lithography
• Focused ion beam patterning
• Reactive ion etching of a wide range of materials
• Direct patterned synthesis of materials
• Electroforming and electroetching
• Theory and modeling of nanopatterning