| 摘要 |
PURPOSE: To accurately control arrangement of PN junction in dopant diffusion, suppress an amount of material converted to N type from P type at minimum and reduce leakage current by using sealing layers composed of two adjacent parts having different doping concentrations. CONSTITUTION: Leakage current of III-V compound semiconductor device is reduced by providing a sealing layer composed of two parts 13 and 14. The first part 14 has a higher doping concentration than the second part 13. An energy barrier which confines minority carriers in the active layer 12 of a device 10 is formed by diffusing dopant in the part of the active layer 12 and in the two parts 13 and 14 of the sealing layer. During the diffusion, although the conductivity type of the part of the low doping concentration second part 13 is reversed, the conductivity type of the high doping concentration part 14 is not reversed. The P type dopant concentration of the sealing layer 13 is approximately 1×10<18> atom/cm<3> or lower, and the P type dopant concentration of the sealing layer 14 is approximately 3×10<18> atom/cm<3> or more. |
