A semiconductor device and method of making the semiconductor device is described. A semiconductor die can be provided. A polymer layer can be formed over the semiconductor die. A via can be formed in the polymer layer. The polymer layer can be cross-linked in a first process, after forming the via, by exposing the polymer layer to ultraviolet (UV) radiation to form a sidewall of the via with via sidewall slope greater than or equal to 45 degrees and to further form a cross-linked via sidewall surface. The polymer layer can be thermally cured in a second process after the first process, wherein a maximum ramp-up rate from room temperature to a peak temperature of the second process is greater than 10 degrees Celsius per minute.