PTC Proposal Seongjin Jang September 09, 2013
Submit Application To PTC • All the users should submit their process-related information to Process Technology Committee (PTC) for approval. • The purpose of this practice is for the PTC to understand exactly what the users are trying to do and to examine the users’ ability to safely perform their tasks. • Once the PTC approves the process, the users will be notified. • The users can use the equipment if they have completed the safety test and equipment training. • Violation of the rules will result in being disqualified.
Example 1: • Fabrication Process Flow • Step 1: 4’’ Silicon wafer with 200nm SiO2, single side polished • Step 2: Photolithography • Image Reversal photo and develop • HMDS, spin coat (coat recipe: firstname.lastname@example.org, email@example.com, 30sec@5krpm to get ~1.8um photoresist) • Prebake (30min, 90C) • Expose (MA6 with mask, 1.0-1.4 sec ) • Post-bake ( 100° C, 25 min or 65 sec 120 °C hotplate) • Flood exposure without mask: (60sec on MA6) • Develop (MIF 422) • Step 3: Ti/Au Electrode Deposition • Standard thermal deposition Target deposition: 70A Ti • Target deposition: 2000A Au • Step 4: Ti/Lift-off • Acetone lift-off on electrode; followed by methanol and 2-propanol for cleaning. • Ultrasonic ~2-3mins for quicker lift-off and clearing lift-off residues. • Cleaning of solvents and contaminants with: acetone / methanol / 2-propanol and multiple rinse dumps. • Step 5: Silicon oxide etch • ICP/RIE etch of silicon oxide • Step 6: Silicon etch • Dry etch of 5 micron Si Substrate using XeF2
Example 1 (cont’d): Fabrication process 1. 4’ wafer with 200 nm SiO2 2. Photolithography 3.Thermal physical deposition of Au/Ti 4. Lift-off 5. ICP/RIE etch SiO2 6. XeF2 etch of 5 micron Si substrate
Example 2: Electrical Characterization of Graphene using Nanomanipulator • Purpose: voltage-current measurements of graphene flakes with electrical contacts • Equipments required: SEM with nanomanipulator or Probe Station • Parameters: Applied voltage (typically less than 10 V) and currents (less than 1 mA) • Note : • The electrical contacts on the graphene will be fabricated outside of the MDL. • Only characterization will be done using the requested equipments.
Example 2 (cont’d): Process Nanomanipulator Probe Or Probe Station probe Graphene Au/Cr Pad Silicon Oxide Wafer