1. Technical Field
The present invention relates to pattern density control, and more specifically, to pattern density control using edge printing processes.
2. Related Art
In a conventional sidewall image transfer (SIT) process, memory regions are formed from a memory layer and then used as a blocking mask for etching one or more layers beneath the memory regions so as to transfer the image of the memory regions down to the underlying layer(s). The formation of the memory regions from the memory layer involves a planarization-and-etchback step. However, the planarization-and-etchback step may have variations due to pattern density variation on the wafer. Therefore, there is a need for pattern density control methods in sidewall image transfer (SIT) technologies and other edge printing processes.