Effect of the variable profile of substrate conductivity on the dynamics of metal deposition on resistive tape

Abstract

The role of the variable conductivity profile κt(x) of the resistive tape in the process of metal deposition on its surface is investigated by comparison two versions of the calculation of process dynamics taking into account non-uniform distribution of the metal and substituting it at each time step for the average thickness of the deposit. It is demonstrated that a narrow κt(x) profile, sharply increasing to the current feeder, promotes substantial improvement of the uniformity of current distribution over the tape but its action is temporary. During subsequent deposition, as a result of the propagation of the deposit over the whole tape length and smoothing the steepness of the conductivity profile, gradual weakening of its leveling ability occurs. It has been established that the factors promoting an increase in the terminal effect (for example, a decrease in the conductivity of the seed layer and in average current density; an increase in tape length) at the same time enhance the leveling role of the κt(x) profile. As a result, the sensitivity of the final deposit distribution over the tape to the initial non-uniformity of deposit distribution (including that caused by the non-uniform initial conductivity profile of the seed layer) decreases sharply.