| 摘要 |
PURPOSE:To increase a channel width and to increase the diameter of a pot by contacting polished surfaces of an N-type semiconductor substrate having a high specific resistance and an N-type base region in clean atmosphere having no foreign material, and heat treating them at 200 deg.C or higher for a short time to contact them, thereby forming an element. CONSTITUTION:A P<+> type layer 11 to become an anode region is formed on one side of an N<-> type silicon substrate 10 to become an N<-> type base of high specific resistance, and a P<+> type layer 12 to become a gate region is formed on the other side. The surfaces of a substrate wafer and an N<-> type silicon substrate 13 to become a cathode side portion, to be bonded are mirror-polished in the surface roughness of 500Angstrom or less. The treated substrate 10, 13 are mounted, for example, in clean atmosphere of class 1 or less, and the polished surfaces are contacted in the state that no foreign material is interposed between the polished-surfaces. The substrate is heat treated at 200 deg.C or higher, and more preferably 1,000-1,200 deg.C for approx. 1hr to obtain a bonding substrate which is increased in the bonding strength. |
