Tabs
Connective tabs keep the release area attached to the rest of the wafer during shipping but are thin enough that they can be easily removed by hand upon arrival.
The TAB masking level is subtracted from the OUTLINE2 masking level to form OUTLINE1 masking level: the final perimeter for the trench etch. A downloadable GDS tab cell file is available here with all the relevant tab geometries. The XZONE masking level ensures no other features are nearby, the TAB masking level defines the connective tabs, and the OUTLINE2 masking level defines the etch on either side of the tab—you will need to add the perimeter of your release area to the OUTLINE2 masking level.
To align the GDS tab cell, the bulk of the TAB masking level should be positioned outside the release area while the "arm" extends into the release area.
 |  |  |
| OUTLINE2 extends into the release area. | TAB arm does not reach into release area. | Correct alignment |
Release area
The RELEASE masking level should should be a solid area that encloses the OUTLINE1 masking level by 100 µm on all sides. The RELEASE masking level will also need to wrap around the XZONE masking level to ensure the connective tabs have a sturdy anchor point.
 |  |
| RELEASE expanded beyond the OUTLINE1 masking level. | RELEASE with cut outs for XZONE masking level. |
General FAQs
What is the metal composition used in the TFE process?
- The metal 1 layer uses 20 nm Ti, 20 nm Pt, 160 nm Au, 20 nm Pt, and 20 nm Ti.
- The top metal layer uses 10 nm Ti + 90 nm Pt.
How is the metal deposited?
- The metal layer is deposited via evaporation with an electron-beam tool.