Harry T. Peters, 1976

Jay T. Last

The article discusses the advantages of ion mobility advantages (IMS) technology in the monitoring of molecular contamination in lithography. It was stressed that advances in IMS allow small, low-cost monitors that have excellent sensitivity and stability. The significance of the technology in a conventional multipoint sampling system includes continuous monitoring of a single sample point, no sampling interruptions or missed contamination events and higher sensitivity to contaminants.

The main goal of this project was to develop new lithographic and nanofabrication approaches for the assembly of novel nanoelectronic and nanomagnetic device structures. Our team's interests, expertise and facilities spanned materials synthesis, nanoscale characterization, nanoscale lithography and processing, and involved three institutions (University of Virginia, Notre Dame University, Lund University). To fabricate annular structures of giant magnetoresistive material for proposed vertical magnetic random access memory structures, we explored use of a novel negative inorganic resist, HSQ. Using electron and ion beam exposure of the resist (as well as direct focused ion beam sputtering of the GMR material) we were able to create structures at or close to the project goal of 75/225 nm internal/external annular diameter. It was found that electron beam exposure offered slightly higher resolution but substantially lower throughput than ion beam exposure of the resist. The resultant exposed HSQ patterns offered good etch masks for physical sputtering of the underlying GMR material, an important consideration given the known challenges in reactive ion etching of these materials. Other studies focused on ultra rapid sputtering of PMMA using focused ion beams and exploring fabrication of inexpensive masks for electron projection lithography. We also explored nanoscale processing and contacting of nanowire structures with our collaborators at Lund University, with application to proposed quantum dot architectures such as quantum cellular automata.

Presents a method for fabricating silicon nanostructures with a scanning tunneling microscope. Involvement of direct chemical modification of hydrogen-passivated silicon surface; Mechanism of liquid etching for silicon nanostructures; Discussion on the lack of etch degradation in the modified surface.