Protocols and Reports

Search results

Now showing 1 - 10 of 74
  • Publication
    Optimization of Bilayer Lift-Off Process to Enable the Gap Size of 1μm Using LOR 3A and S1813
    (2021-01-29) Suh, Yeonjoon; Watson, George Patrick; Suh, Yeonjoon; Watson, George Patrick
    Bilayer lift-off process for 1μm feature size is demonstrated using LOR 3A and S1813 photoresist. The thickness of photoresists was fixed, whereas development time is varied. The process was further investigated by measuring the undercut depth and undercut rate by scanning electron microscopy. An optimized and reproducible recipe is provided.
  • Publication
    KOH etching of (100) Si wafer, No 2
    (2016-09-02) Bajwa, Inayat; Bajwa, Inayat
    This report describes KOH etching of (100) Si wafer through a hard mask of silicon oxide, and reveals that the scattered etch rate is ascribed to the etch rates of the different crystal planes exposed during the etching.
  • Publication
    Effect of Developer Temperature on Photoresist Contrast in Grayscale Lithography
    (2021-05-12) Farnan, Dale; Watson, George Patrick; Farnan, Dale; Watson, George Patrick
    SPR 220-3 photoresist was spin-coated onto a silicon wafer, exposed using a Heidelberg DWL66+ laserwriter at different laser powers, and developed at different temperatures. The effect of developer temperature on photoresist contrast was examined. Results show that increasing developer temperature decreased photoresist contrast and increased required dose.
  • Publication
    Stress in Silicon Oxide Thin Films Grown by Dry Thermal Oxidation
    (2020-11-13) Muduli, Manisha; Yamamoto, Hiromichi; Muduli, Manisha; Yamamoto, Hiromichi
    Dry thermal oxidation is performed at 900, 950, 1000, and 1050 C in fused silica tube furnace (Sandvik)for 10, 20, 50, 100 and 200 min. The properties of the thin-films such as refractive index and stress arestudied in this paper. Refractive indexes of the thin-films are obtained using ellipsometer and decreasesfrom 1.78 to 1.46 as the film thickness increases.Stress of the thin-films is theoretically calculated,experimentally measured and then compared.Stress is calculated theoretically using Stoney’s stressequation and Goklaney’s stress equations. Stress is measured experimentally using the profilometer. Ex-perimentally measured stress and refractive indexes are then compared to discuss the density of the thin-films.
  • Publication
    Comparison between Silicon Nanopillars Prepared by Bosch Process and Metal Assisted Chemical Etching
    (2018-05-29) Chaudhary, Rimjhim; Chaudhary, Rimjhim
    Nanopillars fabricated by Metal Assisted Chemical Etching (MacEtch) wet-etch process have been compared with those by Bosch dry-etch process. The Bosch process in this study gave vertical nanopillars with smooth side walls, which was better than the typical Bosch process. However, the verticality of the nanopillars depended on the location within the wafer where they were etched. On the other hand, MacEtch process gave a very consistent feature from 100 to 1000 nm diameter using 20 nm thick Au film without an expensive etching tool. The present technical report discuss the difference between MacEtch and Bosch processes.
  • Publication
    Metal Assisted Chemical Etching
    (2016-05-25) Bajwa, Inayat; Bajwa, Inayat
  • Publication
    KJLC PVD75 E-beam Evaporator (PVD-04) standard operating procedure
    (2022-04-01) Jones, David J.; Jones, David J.
  • Publication
    Influence of NaOH Concentration on Transfer Process of Graphene
    (2019-09-13) Saldana, Francisco; Wen, Chengyu; Watson, George Patrick; Saldana, Francisco; Wen, Chengyu; Watson, George Patrick
    The process of transferring a monolayer of graphene using two different concentrations of sodium hydroxide (NaOH) solution unto a silicon dioxide (SiO2) coated Si chip using electrochemistry was performed. The transfer process is crucial for the delamination of a continuous graphene monolayer film from copper foil. After examining and inspecting the integrity of the graphene monolayer, it was observed that the lower concentration to NaOH led to slower rate of hydrogen bubble generation; this condition was found to be less destructive and yielded a graphene film with fewer visible tears.
  • Publication
    Progress Report I: Fabrication of Nanopores in Silicon Nitride Membranes using Self-Assembly of PS-b-PMMA
    (2019-03-05) Joshi, Unnati; Venkatesh, Vishal; Yamamoto, Hiromichi; Joshi, Unnati; Venkatesh, Vishal; Yamamoto, Hiromichi
    This progress report describes fabrication of silicon nitride membranes from Si wafers using cleanroom techniques, and of nanopore preparation via a self-assembled PS-b-PMMA film. A 36.9 µm thick membrane is successfully prepared by KOH wet etching. The membrane is a layered structure of 36.8 µm thick Si and 116 nm thick silicon nitride. It is also exhibited that in the 47 nm thick PS-b-PMMA film, the nanopore structure is observed in the vicinity of a dust particle, but most of the area indicates lamellar domain structure. The thickness of PS-b-PMMA film will be optimized to prepare a complete nanopore template in the future work.
  • Publication
    Inkjet Printing of Ag Nanoparticles using Dimatix Inkjet Printer, No 2
    (2017-05-08) Chuang, Ming Yuan
    This report describes the rheological analysisof the present Ag nanoparticle ink, and confirms that it is suitable for the piezoelectric drop-on-demand printing for both of 1 pL and 10 pL cartridges. The satellite drops and the splashing on the substrate are also discussed for optimization of the nozzle temperature and the jetting voltage. The minimum horizontal and vertical line widths are shown to be 30 and 40 µm, respectively, but the average minimum single line width is estimated to be ~50 µm. The non-uniform width lines are suggested to arise from the bulge instability. Furthermore, it is indicated that the surface roughness of the PI film causes the non-parallel contact line pinning. The resistivity of printed lines is also reported.