Grant: Research Tools and Instruments

Micro and Nanofabrication technologies involve multiple complex steps in an effort to fabricate miniaturized structures and devices with a high degree of reproducibility and quality. Among the steps that are essential to make a functional device, deposition of thin films (metals, dielectric materials) are central to any fabrication of micro and nanoscale devices. An electron beam (ebeam) deposition system is an apparatus where an electron beam is produced under high vacuum environment and focused onto the material to be deposited. The atoms of this target are then ejected by the electron flux and are deposited onto a substrate where the micro and nanostructures are produced. Deposition by electron beam provides a highly controlled rate of deposition resulting in a uniform and pristine surface. This technology allows one to conceive and fabricate a collection of nanoscale features over the surface of a single 4"" wafer. In a typical multistep fabrication process, the electron beam deposition system is used repeatedly throughout the sequence. For example, an adhesion layer comprised of titanium or chromium is deposited onto a semiconductor surface prior to deposition of a gold layer. Devices prepared in the Western Nanofabrication Facility typically have 3 or more layers. Layer thickness depends on the role of the layer in the final device and can vary from several nanometers to hundreds of nanometers.***A high quality ebeam deposition system is therefore the key to the success of any advanced fabrication procedure at the nanoscale. The Western Nanofabrication Facility being fully compatible with 4"" wafers, wishes to repair and upgrade an ebeam deposition system capable of processing these wafers. The present system operating in the Western Nanofabrication Facility is an open user apparatus and was produced in the 1980's. Although the evaporator chamber and pumping system are in good condition, the power supply and electronics associated with the settings and focusing of the electron beam gun are obsolete and requires regular servicing and repair which conflicts with an extensive use of this instrument. This instrument is one of the busiest machines in the Nanofabrication Facility. Furthermore, its electronics and safety operation are obsolete by today's standards, which emphasizes the urgent need for a replacement for these control elements at a cost much lower than replacing the entire electron beam lithography system. The new beam control and power supply will provide our researchers with advanced capabilities to explore new methods of fabrication of micro and nanoscale devices.