  The proposal of quantum lithography [Boto et al., Phys. Rev. Lett. 85, 2733
(2000)] is studied via a rigorous formalism. It is shown that, contrary to Boto
et al.'s heuristic claim, the multiphoton absorption rate of a ``NOON'' quantum
state is actually lower than that of a classical state with otherwise identical
parameters. The proof-of-concept experiment of quantum lithography [D'Angelo et
al., Phys. Rev. Lett. 87, 013602 (2001)] is also analyzed in terms of the
proposed formalism, and the experiment is shown to have a reduced multiphoton
absorption rate in order to emulate quantum lithography accurately. Finally,
quantum lithography by the use of a jointly Gaussian quantum state of light is
investigated, in order to illustrate the trade-off between resolution
enhancement and multiphoton absorption rate.
