ИСТИНА

The sheet current model implemented in the program 3D-MLSI for calculation of inductances of multilayer superconducting circuits is discussed in the report. The developed approach and program allow to overcome serious limitations on the shape of the circuits layout and opens the way for effective simulation of internal contacts or vias between layers. Two models for internal contacts are discussed. They are a hole as a current terminal and distributed current source. Advantages of the eveloped approach are illustrated by calculating the spa- tial distribution of the superconducting current in several typical layouts of superconducting circuits. The numerical procedure is based on Finite Element Method and effective triangulation of overlapping multilayer structures. The algorithm can be applied to structures of variable thickness and non-planarized fabrication processes.