The challenges in materials design for 157nm photoresists

Developing 157nm lithography capability in time for production requires the solution to several daunting materials challenges. Among the most difficul t of these is finding a suitable 157nm photoresist. The transitions from i- line to DUV and from DUV to 193nm both required development of new material s because the old ones were opaque at the shorter wavelength. Again, resear chers are learning that all existing imaging materials were opaque at 157nm and that they must search for materials capable of balancing the requireme nts of transparency, etch resistance, and developer solubility. Encouraging progress is being made, but much remains to be done in a very short time.