Past exam of the MPhil in micro- and nanotechnology enterprise course of the University of Cambridge / 2019 / Paper 1 / Section A(ii) / 4 / i / Solution

Solve the stated depth of focus relation before substituting into the resolution expression:This uses the supplied empirical $k_1$ and $k_2$ unchanged and interprets $R$ as the minimum line or space width of an equal-line/space square grating. Under that convention its pitch is $2R=578.6\mathrm{nm}$. Other pattern shapes or a different definition of the quoted depth of focus would require different process factors.