Etch bias control

A method for forming a device comprising:

• providing a patterned reticle comprising a reticle perimeter which includes a target reticle perimeter defined by total length of circumference of active and dummy patterns, wherein
• the active patterns are disposed in a device region and the dummy patterns are disposed in the device region and a frame region, the frame region surrounds the device region,
• the dummy patterns comprise modified dummy structures, and
• a modified dummy structure includes one or more slots or voids therein and the one or more slots or voids are tailored to achieve the target reticle perimeter to produce a desired etch bias;
• forming a resist layer on a substrate with a device layer;
• patterning the resist layer using the reticle to form a patterned resist layer containing active and dummy patterns of the reticle;
• performing an etch to pattern the device layer using the patterned resist layer, wherein the patterned device layer includes active and dummy patterns of the reticle;
• and
• performing additional processing to complete forming the device.