The Michigan Nanofabrication Facility (MNF) is located in the Electrical Engineering and Computer Science Building and operated by the Solid State Electronics Laboratory. The facility first opened in September 1986 and was fully operational in 1988. It was renamed Michigan Nanofabrication Facility in January 2005. http://www.mnf.umich.edu/ It consists of a Class 1000/100/10 research laboratory with approximately 6,000 square feet of work area and a separate Class 10,000 instructional laboratory of approximately 1,000 square feet which supports formal courses. The research laboratory consists of five process bays (silicon lithography/diffusion, silicon LPCVD, compound semiconductor devices, thin-film deposition, and dry etching) plus five separate, connected rooms for e-beam lithography and metrology (Class 10) and for compound semiconductor materials growth.

The MNF is supported by a lab manager and a staff of 12 engineers and technicians whose primary responsibility is to ensure that the equipment is well maintained and characterized. In addition, the MNF has four staff members whose primary responsibility is to provide training and support users and their projects. The MNF also employs a full time staff engineer for support of the instructional laboratory, which also relies on teaching assistants; graduate students and process engineers for support of the classes. Graduate students perform most of the processing in MNF as part of their doctoral thesis projects. There are also five process engineers who continually process complete devices for specific research projects. The facility is also used by a number of local firms, both large and small, by other universities, and by remote users who can send in their orders to be processed by the laboratory staff.

LAM 9000 Reactive Ion Etcher

 
The various SSEL fabrication capabilities are described below:

• Lithography: All of the optical lithography performed in the SSEL is based on contact aligners operating in the UV and deep-UV. This equipment includes Karl Suss MA45 aligners (2) in the Instructional Laboratory, a Karl Suss MA-6 equipped with infrared in the silicon bay, and two Karl Suss MJB3 aligners, one of which is equipped with an excimer laser source (0.193 micron). An Electronic Vision double-sided aligner / bonder is also located in this laboratory. The optical lithography process is well defined at 0.9-micron features. Below that point, a JEOL 5D2F/U electron-beam lithography system is available for the direct writing of features to less than 0.10 micron. This system has been operational since late 1986 and has a minimum spot size of 8 nm. This e-beam lithography system is being upgraded at the present time to even smaller spot size.
• Diffusion, Oxidation, and LPVD: A total of 24 Thermco furnaces are available to support high-temperature processes. Twelve of these are equipped with computer-driven (menu screen) DDC controllers, providing automatic control of time, temperature, gas sequencing, and boat insertion / withdrawal. The rest have automatic sequencers for gas control during the run cycle, with manual control of temperature and sample loading. All tubes are equipped with all standard process gases (including TCA for in-situ cleaning), and are equipped to support four-inch wafers. Wet chemistry benches support the furnaces and spin dryers dedicated to ensuring proper cleanliness. Cross-contamination is controlled by dedicating tubes to specific process including wet and dry oxidation (four tubes), boron (B) and phosphorus (P) pre-deposition (three tubes), P and B atoms drive-in (two tubes), and contact sintering (one tube). These processes are duplicated in the eight furnaces in the Instructional Laboratory, providing valuable backup capability. Three tubes are dedicated to compound semiconductor processing, and one tube is used exclusively for polyimide curing. Three of the DDC tubes are configure for LPCVD, one for oxide / nitride / oxinitride, one for polysilicon, and one for LTO / PSG. Non-uniformity from the LPCVD processes is typically less than two percent across a four-inch wafer.
• Materials Growth / Epitaxy: There are several facilities for materials growth using various forms of epitaxy, including a Riber molecular-beam epi reactor (MBE), a Varian Gen-II MBE, a Varian metal-organic MBE (MOMBE), and an Emcore metal-organic CVD (MOCVD) system.
• Thin Film Deposition: The SSEL is well equipped for the vacuum deposition of a wide variety of materials. A Commonwealth Ion-Beam Milling and Deposition System, four electron-beam evaporators (two Denton and two Lesker), a Lesker four-target sputtering system, and a CVC thermal filament evaporator are on-line for work in this area. A SEMI Group plasma-assisted PECVD system is also available.
• Etching / Pattern Transfer: Process benches support wet chemistry to etch a broad range of semiconductors, dielectrics, and metals. The SSEL also offers a broad range of dry etching capabilities, and many specific processes have been characterized. Equipment includes an Applied Materials 8300 hexode reactive ion etching system (RIE), a SEMI 1000Tp/C planar dual-chamber RIE, a SEMI plasma etching system, A Plasma Therm ECR RIE system, a Plasma- Therm VII Dual Chamber RIE, and a Technics parallel-plate plasma etching station.
• Metrology: The SSEL has extensive facilities for process characterization and metrology, including single-wavelength (Geartner Ellipsometer) and spectroscopic elipsometry (Sopra Ellipsometer), microspectrophotometry, surface profilometry (Vecco Dektac 8000 and 1600), thin film stress measurements, DLTS, photoluminescence, high-resolution optical microscopy, and a JOEL 840 scanning electron microscope. In addition, access is also available to research laboratories such as the Michigan ion Beam Laboratory (MIBL) and the Electron Microbeam analysis Laboratory (EMAL).
• Bonding and Mounting: The SSEL includes a Hughes VTA-90 split-tip microwelder, two Kulicke and Soffa ultrasonic wire bonders, and a Kulicke and Soffa thermocompression bonder. Both a homemade electrostatic wafer bonding setup and commercial system are available to increase bonding throughput and yield.
• Computer-Aided Design (CAD): The College of Engineering operates the Computer aided Engineering Network (CAEN), the backbone of which is an installation of over 1400 engineering workstations: http://www.engin.umich.edu/caen. These facilities support virtually the full set of Mentor, Cadence, TMA and Cascade design automation packages, as well as point tools from other vendors, providing circuit design, synthesis, layout, simulation, parameter extraction, verification and tape-out for VLSI circuits, as well as process and device simulation. Masks are made on our in-house system or by outside vendors. The Cerius2 version 4.6 molecular modeling software (Molecular Simulations, Inc.) is also available for this group.