Improved MRAM arrays and a method of forming the same are disclosed in which a bit line has thinner portions formed over MTJs and thicker portions therebetween. Next, each electrical interconnect is encased in a dielectric and the dielectric is sectioned to expose a portion of each interconnect. A carbon-atom containing gas is supplied to silicon carbide substrate from a point of time in the step of performing the vapor phase etching. A control unit individually controls the power control units based on detected signals output from the detecting units. This information is then employed to generate a graphical user interface including a multi-dimensional map to represent the attribute information, and the electronic content, where the multi-dimensional map comprises at least color, size and direction characteristics. The external circulation path is constructed from a pipe with a circular cross-section.