Filler and tap-cell insertion

Filler and tap-cell insertion. Placement leaves gaps between the cells in each row. Two finishing steps close the design out:

• Rows continuous - fill every gap with filler cells so the follow-pin power rails and the wells stay unbroken. An exposed site breaks the rail (you can see the gap in it). Use the filler tool: click a gap to fill it.
• Every site within tap reach - drop well-tap cells so no point in a row is farther than the tap reach (the green band), the rule that prevents latch-up. Taps only fit in the gaps, never over a placed cell, and each one costs area, so cover every site with as few taps as you can. Use the tap tool.

Fill the rows and tie the wells, then Submit design.