DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0026] The present inventors first formed barrier layers and seed layers by CVD according to conventional techniques. [0027]FIGS. 4A and 4B are a cross sectional view illustrating a main process of forming samples and a graph showing the characteristics of samples. [0028] As shown in FIG. 4A, on a p-type Si substrate 10 with a silicon oxide film 1