Preparing an Aging Facility to Meet Expanding Lab Demands: Renovation of the Stanford Nanofabrication Facility PDF

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The Stanford Nanofabrication Facility at Stanford University is housed in a building approaching 30 years in age. The ability of the program to meet research needs is increasingly hampered by the capacity and age of the physical structure. In late 2010, the Stanford Nanofabrication Facility was awar...

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Preparing an Aging Facility to Meet Expanding Lab Demands: Renovation of the Stanford Nanofabrication Facility John D. Shott, John W. Bumgarner, Mary X. Tang Stanford Nanofabrication Facility, Stanford University Palo Alto, CA. [email protected], [email protected], [email protected]

Abstract: The Stanford Nanofabrication Facility at Stanford University is housed in a building approaching 30 years in age. The ability of the program to meet research needs is increasingly hampered by the capacity and age of the physical structure. In late 2010, the Stanford Nanofabrication Facility was awarded funding from the National Science Foundation, and matched by contributions from the University, to begin a renovation program that addresses these infrastructure shortcomings. This paper describes the key tasks undertaken and the challenges of executing a construction project of this nature with minimal impact to ongoing research. We conclude with lessons learned. Background: At the dawn of the silicon semiconductor age in the mid-1960’s, Stanford researchers were processing electronics devices in a new basement laboratory. The industry and the research soon outgrew the lab. To meet the growing need for integrated cleanroom infrastructure to support industrial tools for electronics-based processing, the Paul G. Allen Center was completed in 1984. Its 10,000 sq.ft. cleanroom currently houses the Stanford Nanofabrication Facility (SNF). As far as we know, this is the oldest university cleanroom facility of this type and size still in operation. And its age poses certain challenges in meeting the dynamic needs of our researchers in the following ways: 1. As building codes evolve, it is increasingly difficult to obtain permits for new tools or even upgrade old ones; 2. Newer tools demand more utilities support, thus taxing the limited capacity of our existing building systems. 3. Researchers demands for new materials and new chemistries requires flexible infrastructure to support delivery, handling, abatement and waste management. In 2009, NSF announced the Academic Research Infrastructure Program: Recovery and Reinvestment

(ARI-R2) to “revitalize existing research facilities so that they provide next-generation research infrastructure and facilitate the integration of researchers with shared resources…” SNF submitted a proposal and was awarded $4.2M. Stanford University contributed an additional $2.4M. Construction began in November and continues now. The key challenge for the management of this project has been the requirement that construction activities should have minimal impact on research endeavors. Thus, the schedule was pushed aggressively to coordinate activities requiring complete lab shutdown with the annual University-wide shutdown in December. With a capable crew, team-work and frequent communication with stakeholders, the critical path construction activities were completed one week ahead of schedule, allowing SNF staff to begin reoccupying the lab on February 1. Task Descriptions: Toxic Gas Monitoring (TGO) System. Evolving code requirements and hardware obsolescence made it increasingly difficult to support and maintain the TGO system. With over 100 detection points, it used four different sensor models, two of which were at end-oflife, and two different communications protocols, one of which had become obsolete. The PLC control system, while still supported, was also slated for end-of-life. Moreover, as code requirements and TGO administration had evolved over the years, our overall detection approach was not self-consistent, as was called out by local HazMat inspectors on several occasions. In the renovation, the hardware for the TGO system was completely replaced. Most notably, the detectors are now a combination of the DoD PS7 electrochemical sensors (modular, flexible, and durable) and the CL-96 tape system (higher sensitivity for arsine detection.) These “draw-type” sensors are mounted on strategically located panels, with individual draw-tubes distributed to test

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locations. This configuration allows for easy maintenance and monitoring, as well as reduces the cost of modifying or adding new test points. In addition, number of test points was expanded to 146, following best-practices for gas monitoring. The new system was designed with extensive input from the local jurisdiction and was put into service in early February of this year. Process Gas Distribution and Management. For safety reasons, hazardous process gases are supplied to the lab from reinforced storage bunkers via 400 ft of gas lines. Prior to the renovation, no spare lines were available and connections to new tools were made by extending existing tool supply lines in the lab. Thus, requests for new process gas went unsupported because it was either cost-prohibitive to install a new gas line or difficult to isolate the tool of interest from the others supported on an existing gas line. The renovation allowed installation of 6 new gas lines and gas cabinets with autopurge panels, each of which terminates in a valve manifold cabinet located just under the lab to allow more flexible, cost effective hookup and isolation of new tools. Additional plans are underway to replace the remaining 30-year old manual purge cabinets with newer, safer, and cleaner autopurge systems. Utilities Capacity. The installation of utility-hungry and environmentally demanding tools in recent years have maxed the capacity of the building, prompting the following upgrades. PROCESS COOLING WATER Piping in key distribution legs were upsized and additional booster pumps were installed to increase available flow and pressure. Chemical treatment system was installed to minimize corrosion in tools. ELECTRICAL DISTRIBUTION – Although there was sufficient power in the building, distribution of power to the lab fell short of new tool requirements. Additional transformers were installed and distribution boxes placed directly under the lab for easy access to lab tools. SOLVENT EXHAUST CAPACITY – Exhaust requirements of recently installed resist handling tools required the existing exhaust fan to run at maximum speed. An upsized fan system and larger ducting provides additional capacity and should eliminate fan failures previously experienced. HUMIDITY CONTROL IN PHOTOLITHOGRAPHY – Upgrades to the water injection and mixing systems in the air handlers will improve the robustness of the environmental controls to rapid changes in the outside temperature and humidity. “Flexible” Chemistry Lab. Increasingly, the SNF process review committee has been rejecting special requests for chemical processing for reasons of safety: a wet bench simply does not have the same safety features as a chemical fume hood. Moreover, because the SNF runs 24/7, is well-populated and heavily shared (over

200 users per month), tighter constraints are imposed on the types of processing allowed. To meet researchers needs, the new nSil (nano-Structure Integration Lab) will be designated as a flexible chemistry space, containing chemical fume hoods and supporting equipment. Located next to the cleanroom, but in a separate lab space, it will provide a controlled and supervised area where students can learn and experiment with basic chemistry processing. Serving primarily nonchemists, it is expected that the processes supported will complement cleanroom processes, i.e., basic chemistry to modify, functionalize, and manipulate nanoparticles and nanostructures, as well as integrate them with devices and other structured materials. Building Code Compliance. Numerous tasks to be address in this renovation project are aimed at bringing key features of the building and lab up to current code. These tasks include: installation of additional fire sprinkler protection, replacement of Halon fire protection, seismic bracing of fire protection systems, replacement of single-walled waste piping with doublecontained piping, upgrade of fire doors, replacement of wet benches for fire-resistant construction, seismic bracing of tools. Conclusions: This renovation will extend the useful life of this facility for another 10-15 years. This will allow us to better meet the needs of our researchers – as well as allow the University time to re-imagine the SNF of the future. One observation: research is going beyond silicon and researchers would like to explore the periodic table. Though we can’t predict researchers’ needs over the expected lifetime of a lab of perhaps 25-30 years, facilities need to be prepared to be more flexible than ever in meeting these ever-changing demands. A welldesigned facility should have safety and utilities infrastructure to readily support changing tool requirements and for cradle-to-grave management of new materials, chemicals, and gases....