Optimization of the Uniformity of the Contact Resistance (Rc) of the via by the Collocation of Gas Parameters in AIO Etching

All-In-One (AIO) etching is commonly employed to define smaller-scale through-holes and trenches in advanced CMOS technology nodes with Cu/low-K interconnects. During the etching process, the collocation of various parameters in the recipe will have a certain effect on the uniformity of the via contact resistance (Rc) and Rc after profile , via/trench CD and final molding, among which the average value and uniformity of the via contact resistance (Rc) are particularly important. In this paper, we found that the addition of H2 to the via etch characterizes the reduction of polymer in the signal of the PR removal step CN, and has a significant improvement in the mean and uniformity of the via contact resistance (Rc).