Ebara Corporation

Kenji Amaya

Matsuho Miyasaka

Shigeru Aoki

Hirokazu Takayama

A plating analysis method is disclosed for electroplating in a system in which resistance of an anode and/or a cathode cannot be neglected. This method comprises giving a three-dimensional Laplace's equation, as a dominant equation, to a region containing a plating solution; discretizing the Laplace's equation by the boundary element method; giving a two-dimensional or three-dimensional Poisson's equation dealing with a flat surface or a curved surface, as a dominant equation, to a region within the anode and/or the cathode; discretizing the Poisson's equation by the boundary element method or the finite element method; and formulating a simultaneous equation of the discretized equations to calculate a current density distribution i and a potential distribution &phgr; in the system. The method can obtain the current density and potential distributions efficiently for a plating problem requiring consideration for the resistance of an electrode. The method also optimizes the structure of a plating bath for uniformizing current, which tends to be concentrated in the outer peripheral portion of the cathode, thereby making the plating rate uniform.

Plating analysis method

An object to be analyzed for corrosion and corrosion prevention is divided into a plurality of adjacent regions of plural types by a dividing plane, with one of the adjacent regions being referred to as an attentional region with a boundary as the dividing plane and the other as a non-attentional region with a boundary as the dividing plane. An initial current density or an initial potential is imparted to each element of the boundary of the non-attentional region to effect a boundary element analysis for determining a relationship between a potential and a current density in each the element. A potential distribution and a current density distribution in the attentional region in its entirety are determined, using the relationship between the potential and the current density in each the element of the boundary of the non-attentional region as a boundary condition for the attentional region.

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Kawasaki, Japan

Kenji Amaya