What Happened To Inverse Lithography?

Nearly 10 years ago, the industry rolled out a potentially disruptive technique called inverse lithography technology (ILT). But ILT was ahead of its time, causing the industry to push out the technology and relegate it to niche-oriented applications. Today, though, ILT is getting new attention as the semiconductor industry pushes toward 7nm, and perhaps beyond. ILT is not a next-generation ... » read more

Taming Mask Metrology

For years the IC industry has worried about a bevy of issues with the photomask. Mask costs are the top concern, but mask complexity, write times and defect inspection are the other key issues for both optical and EUV photomasks. Now, mask metrology, the science of measuring the key parameters on the mask, is becoming a new challenge. On this front, mask makers are concerned about the critic... » read more

Impact Of Illumination On Model-Based SRAF Placement For Contact Patterning

Sub-Resolution Assist Features (SRAFs) have been used extensively to improve the process latitude for isolated and semi-isolated features in conjunction with off-axis illumination. These SRAFs have typically been inserted based upon rules which assign a global SRAF size and proximity to target shapes. Additional rules govern the relationship of assist features to one another, and for random log... » read more