OXIDE ETCH - WET

Important Notes:

  1. Use your own designated Teflon or plastic etch beaker to prevent contaminating your wafers. If your wafers are already gold contaminated you may use the beakers on holders at the wbgeneral (all of them are gold contaminated). Once you use a contaminated beaker -- your wafers must be considered contaminated and are restricted as to what equipment they may use (see MATERIALS )

PROCESS

  1. Check etch rate of the etch you plan to use. Most people either use 6:1 Buffered HF or 20:1 Buffered HF.
  2. Using your own designated beakers and holders for this bench, dip test wafer in DI water for 15 seconds.
  3. Immerse in Buffered HF for calculated etch time. Note: It is sometimes useful to clear a patch of resist near the edge of the wafer to watch for it to go hydrophobic to determine the etch time required. This can be done using a QTip and Acetone for positive resist.
  4. Overflow rinse for 5 minutes.
  5. Blow dry
  6. Inspect for undercutting and measure to be sure oxide is removed.
  7. Process the rest of the wafers (steps 2 through 6).