Challenges In 3D Resists

3D integration straddles the line between CMOS fabs and packaging and assembly houses. Depending on the structure being fabricated, the most appropriate process might be more “CMOS-like” or more “package-like.” For example, in CMOS fabs lithography means spin-on photoresist, exposed by a high precision stepper. Inherent in this approach is an assumption that the wafer surface is flat... » read more