Abstract

Quantum lithography promises, in principle, unlimited feature resolution, independent of wavelength. The price to be paid is that the lithographic film must consist of a multi-photon absorbing material. If N photons are absorbed, the minimum feature resolution goes from roughly λ/2 to λ/2N. However, there has been a discussion in the literature as to what is the probability of N photons in a lithographic exposure field to hit the same detector pixel, thereby enabling the needed N-photon absorption. On one hand it has been claimed that “If the optical system is aligned properly, the probability of the first photon arriving in a small absorptive volume of space time is proportional to [the field intensity]. However, the remaining N-1 photons are constrained to arrive at the same place at the same time…” [1]. On the other hand it has been argued that “… it is not true that the first arriving photon greatly constrains the arrival location of the following ones … Very few photons will be absorbed in one point since they typically arrive far apart.” [2]. The answer to this dispute dictate very much the practical feasibility of quantum lithography, because if the few photons in the entangled state are spread out over the exposed area, the probability will quickly become negligible that they arrive at the same spot (causing a N-photon detection event). This will render quantum lithography very inefficient, albeit still feasible in principle.

© 2011 IEEE