抄録
A new method, combination of a boundary element method and a finite element method, has been developed to simulate the electroplating of a silicon wafer with copper. In this method, the Laplace equation is solved by representing the complicated phenomena near the anode and cathode surface as polarization characteristics (PCs) and using the PCs as nonlinear boundary conditions. The electrical resistance distribution of thin copper and TaN films on a silicon wafer is then taken into account. To make a uniform copper film, the anode (copper plate) is divided suitably into several pieces. To design the size of each multiple anodes rationally, the ideal anode current density distribution which is obtained by solving inverse problem are used. In the inverse problem both of the potential and the current density on the cathode are given as the ideal values, i. e., the uniform current density and its corresponding potential. Optimization of current to be supplied to each piece of the anode is performed by employing the Simplex method.
