Process evaluation of pyramidal and cone-shaped nanoparticle deposition (NPD) bumps using a thermally resistant resist

In this paper, an i-line resist with possible high thermal stability is evaluated to ascertain the effect of temperature on the resist profile during the nanoparticle deposition process. Apart from cone-shaped bumps, pyramid bumps were also evaluated in terms of the exposure parameters and the bump profile formed after the NPD process. Using the i-line resist, 5 μm and 7 μm bumps were realized in a single nanoparticle deposition process, with an aspect ratio of 1.2.