Center for Nanoscale Systems (CNS)

Since October 2021, I’ve been interning at Center for Nanoscale Systems (CNS), Harvard’s nanoscale fabrication and integration facility. Working under Jiangdong Deng, lead for the Nanofabrication facility, I’m tasked with assisting in the design and manufacturing of devices used for other research groups.

Training

As of January 2022, I am trained in cleanroom protocol, acid/base and developer wet bench usage, spinner usage, and photolithography development. I am trained/training in and use the following tools:

  • Photolithography - Heidelberg Instruments Maskless Aligner 150, SUSS Mask Aligner MA6, YES HMDS Oven, Headway Spinner PWM32
  • Scanning Electron Microscope - Hitachi SU8230
  • Sputtering Systems - AJA ATC Orion 9, Orion 3
  • Chemical Vapor Deposition Systems - STS PECVD, Cambridge Nanotech Savannah S200 ALD
  • Dry Etching Systems - Anatech SCE 106 Quartz Barrel Plasma System
  • 4-Point Probe Measurement Device - ResMap 178
  • Optical Profilometer - Bruker ContourX-500, Taylor Hobson CCI HD
  • Stylus Profilometer - Bruker DektakXT

Additionally, I’ve used the following software packages for nano-scale design:

  • Imaging: Nikon NIS Elements
  • CAD: SolidWorks, Fusion 360, AutoCAD, LinkCad

I’ve also taken lectures on Thin Film Processes, Dry Etch Processes, Photolithography, and Metrology.

First Project

My first project involves the design and fabrication of nano-scale coils used in neurological experiments for a collaboration between my supervisor and the Analog Brain Imaging Lab. The project builds on Jeong et. al. ‘s previous work on planar figure-8 coils for nerve stimulation[1]. Given design specifications and device illustrations, I’ve come up with a digital design and a process flow.

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I’ve trialed the first process flow (resist coating, exposure, development, initial inspection with optical microscope), reporting high photoresist stress, underexposure, and low development time. Based on my observations and my supervisor’s guidance, I’ve altered the design to relieve stress and increase ease of alignment.

opticalmicroscopeviews

 

newdesigns

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This project is a work in progress. It will be updated as developments occur.

Last update: December 2021.

References

[1] H. Jeong, J. Deng, and G. Bonmassar, “Planar figure-8 coils for ultra-focal and directional micromagnetic brain stimulation,” J. Vac. Sci. Technol. B, vol. 39, no. 6, p. 063202, Dec. 2021, doi: 10.1116/6.0001281.