Graduate student Dave Wollman is shown using the mask aligner




Director
	Dale Van Harlingen
   	106 MRL	
        333-0904
        Email:  vanharlingen@uimrl7.mrl.uiuc.edu


The MRL Microfabrication Laboratory provides facilities and capabilities for the in-house deposition of thin film materials and the microfabrication of patterned structures and multilayer electronic devices. The objectives of the lab are to support the growth of a wide variety of thin film materials, to allow rapid implementation of device designs, and to achieve state-of-the-art specifications for minimum line width, alignment accuracy, and interface control. At present, we are able to obtain features down to about 200A using direct write electron beam lithography and liftoff procedures, and medium-scale integration density circuits over about 5cm x 5cm using optical contact lithography.


The lab consist of three major facilities:


(1) A Class-100 clean room that houses laminar flow benches and spinners for the wet-chemistry procession of photoresists, and an assortment of optical microscopes, annealing and processing ovens, and electronic lead bounders, and an optical mask aligner (Karl-Suss MJB3) for optical lithography.

(2) A thin-film deposition lab that contains a wide range of equipment for the growth and procession of thin films. Included are an ion milling/thermal evaporation system for fine line patterning and surface modification, a three source rf/dc/dc magnetron sputtering system, and a newly-constructed sputtering/evaporation chamber dedicated to refractory superconductor tunnel junction fabrication, especially Nb-trilayer devices. A reactive ion etching system has been requested to add submicron pattern delineation capabilities to the lab.

(3) A scanning electron microscope (JEOL-6400) configured as an electron-beam lithography system. This system allows computer generation of thin film patterns by computer control (Nabity Lithography System). This microscope is used for both direct-write electron beam lithography and for small-scale photomask production. large scale mask patterns are available locally from the commercial electronbeam lithography system (Cambridge EBMF-10.5) housed in the UIUC Microfabrication Center.


Currently, the lab serves about 50 users from 10 research groups. The major use is from investigators in the MRL Mescopic IRG, including Van Harlingen, Weissman, Salamon, Gibson, and Greene. The Microfabrication Laboratory is an essential element of most of the research of this group. Devices being fabricated and studied includes submicron tunnel junctions, dc SQUIDs, nanoscale resistors, periodic superconductor arrays, ensembles of magnetic islands, layered magnetic materials, high temperature superconductor structures, superconductor-semiconductor hybrid structures, and mesoscopic rings. The lab is also made available to other users in the MRL-DOE program, the Science and Technology Center for Superconductivity, and the College of Engineering.