• Design inside a 4” wafer

When turning your devices into a mask, you will place your device design inside a 4” circle that defines the size of the silicon wafer.

• Center your wafer inside a 5”x5” square

The mask will be taped to a borosilicate glass of such dimensions. By centering your wafer to this square alignment of the photomask much easier.

• Use the space in the wafer efficiently

  Try to fit in as many devices as possible onto a single mold. Label each copy with a unique device number so you can keep track of them. However, ensure to leave enough spacing so you can cut individual devices.

• Avoid having features near the edge of the wafer

  Leave a 3-4mm gap. After spin-coating photoresist you will have an edge bead effect around the wafer, particularly for thicker layers, and you cannot utilize that area for building a mold.

• Include identifying information inside the wafer.

  The following details must be included: name, date, mold name, mold version, layer name (for multi-height/multi-layer). Also useful: project name.

• Be generous with alignment marks (crosses or squares) if you will be including multiple feature heights on your wafer.

• Masks are generally printed on 8.5" x 11" transparency sheets.

  Therefore, a total of four molds in four quadrants can fit on each sheet. If you have several chip versions which do not fit onto one mold, design a second mold in another quadrant.

• Save your file as a .dwg

The company that will translate your design will use the .dwg file type.