Although the production method of PN Junction is identical to the diffusion type, only the PN junction and its necessary parts are retained, and the unnecessary parts are corroded by medicines. The remainder of the section presents a surface form, hence the name. The mesa type of the initial production is made from the diffusion method of semiconductor materials. Therefore, this type of surface is called the diffusion table. For this type, it seems that there are few models for large current rectifier, and the small current switch is a lot of product models.