Dr. Vicky Diadiuk MTL Associate Director, Operations Massachusetts Institute of Technology

1. Mission Critical Tools at MIT’s Microsystems Technology Labs Dr. Vicky Diadiuk MTL Associate Director, Operations Massachusetts Institute of Technology

2. Support EDUCATION (graduate & undergraduate) through research in semiconductor devices and processes Support RESEARCH in micro- & nanosystems, technologies and structures Provide FACILITIES and infrastructure for research in micro- & nanosystems and associated technologies MTL Mission

3. Fabrication(Supported by 16 Technical Staff) Integrated Circuits Laboratory (ICL) Class 10 – 2,800 sq.ft. (6”, some 4” & pieces) Mostly CMOS compatible processes Silicon, Germanium, Quartz, III-V, GaN Technology Research Laboratory (TRL) Class 100 – 2,200 sq.ft. (up to 6”) Flexible Processing Silicon, III-V, Glass, Organics, Polymers Exploratory Materials Laboratory (EML) Class 10,000 – 2,000 sq.ft. Thin Film Processing Facility Electron Beam Lithography Laboratory (EBL) Class 100 – 400 sq.ft Elionix EFS-125; operated jointly with RLE MTL – Infrastructure (Fab and CAD) CAD and IT(Supported by 4 Staff) • CAD platforms; foundry access

4. 2015 User Distribution by Primary Research Area & Material (from Self-Reported Data) Fab Users = 412

5. MTL Research Activities: Length Scale Magnetic Domain Wall Logic Devices (Baldo) 320 GHz RX chip for Coherent THz Imager (R. Han) Flexible Tactile Sensor (Lang) MoS2 FET (Palacios) Graphene Nanoporous Membrane (Karnik) AC-DC Power Factor Correction Circuit Architecture (Perreault) Roll-to-Roll Graphene Transfer Tool (Kong, Palacios) InGaAs FinFETs (del Alamo) Microhydraulic Actuator (Kim) Si Field-Emitter Array (Akinwande) Slide courtesy of Jesus del Alamo

6. Meets weekly to review and approve new processes, materials and protocols; reviewed within 1 week of submission. Interviews users who request 24-hr status Is composed of 3-4 faculty, 4 students/post-docs (who serve for 1 year), rotating MTL Specialists and the Assoc. Director of Operations, who chairs it Provides process advice, since members cover different research areas Maintains and updates the PTC Matrix PTC members are available for assistance with processes or questions on new materials, protocols, etc. The Process Technology Committee (PTC) Key to avoiding cross-contamination among processes

7. PTC Matrix http://mtlweb.mit.edu/services/fabrication/ptc_matrix.html

8. How to use the PTC Matrix Y- axis: Machines (by lab); X-axis: wafer attributes Some Wafer attributes are permanent (*), some are added by a machine (o+), some can be removed by a machine (o-) An o indicates that a wafer is allowed in that tool, an x that it isn’t

9. Major Fab Areas • Diffusion: atmospheric & LPCVD furnaces; RTP • Photolithography: mask-aligners, stepper • E-beam Lithography: Elionix EFS-125 • Dry Etch: various chemistries, depth, wall angle • Deposition: PECVD, e-beam, sputtering • Wet Processes: clean, etch, release • Metrology: thickness, index, morphology • Packaging: CMP, die-saw, wire-bond http://mtlweb.mit.edu/services/fabrication/equipment.html

10. Periodically, fabs need to replace tools & acquire new capabilities New research directions, as well as some traditional projects, often need special tools, that are useful to general users, so they belong appropriately in shared cleanrooms. Examples are: • RIE & DRIE for various materials (Si, III-Vs, etc) • Deposition systems for CNT, graphene & other 2D materials & the corresponding transfer hoods So how does the MTL shared facility acquire process tools? Need Tools for New & Traditional Research Directions

11. Industrial donations - very selective on what is accepted MTL acquisitions - with MIT capital equipment replacement funds Individual research grants - tools may be fully shared or mission-critical; no private tools are allowed in cleanrooms (due to space limitations & management issues) What is a mission-critical tool? - Group that acquires mission-critical tool still pays fabfees - May get some reserved-use time - Can veto materials that would compromise “the mission” - Restrictions get captured in PTC Matrix - Advantages to the group: professional maintenance, shared consumable costs MTL staff maintains and supports all tools; develops basic processes Tool Acquisition Modes at MTL

12. Examples of Mission Critical Tools Angstrom Engineering EvoVac deposition system • Sputtering, e-beam and thermal evaporation Funded by a research grant Mission restriction: CMOS metals only Applied Materials Centura 5200 dielectric deposition system • PECVD of very tightly controlled Si nitrides an oxides Donated to a research group by the OEM Mission restriction: no metals on wafers STS Multiplex ICP DRIE system • Deep RIE of Si Funded by a research grant Mission restriction: no polyimide

13. MTL provides shared fabrication facilities that: Provide hands-on training in micro- and nano-fabrication Enable researchers to cross disciplinary boundaries Encourage free flow of information across projects and technologies Careful control of process flows avoids cross-contamination Provide access to a large variety of tools, obtained by: donation, internal & research-grant funding No private tools are allowed, but tool-level restrictions are acceptable for mission critical machines; this has enormous benefits for the entire nano/micro- fabrication community Summary

14. Thank you for your attention 

15. Sample Process Using the PTC Matrix User Jorg Scholvin programmed the PTC Matrix in Excel Basic for auto-checking THANKS!