3. A circuit design requires a maximum permissible current density of 5 x 10- A/cm through a conductor 1 mm long, 1 um wide and nominally 0.5 um thick. This conductor goes over steps where it is thinner on the vertical walls of the steps. Assume that 10 % of the conductor length is over the vertical walls of steps where it is 0.25 um thick. What maximum voltage may be used across the conductor if the sheet resistance is 5.6 x 10"- 2/square? Thinner on the vertical Conductor wall