| 摘要 |
PURPOSE:To obtain sensitivity high enough to detect infrared radiation of long wavelength and reduce the noise by a method wherein the forbidden band width of a surface region is made wider than that of a bulk region including a P-N junction. CONSTITUTION:A compound semiconductor layer 2 which is approximately 2,000Angstrom thick and has a wide forbidden band is formed on a semiconductor substrate 2 which has a narrow forbidden band and is covered by an insulating film 3 of approximately 5,000Angstrom thickness and an aperture W is made. An impurity diffused layer 10 of approximately 5,000Angstrom thickness and an aperture W is made. An impurity diffused layer 10 of approximately 5,000 deg.C depth is formed and is covered by an insulating thin film 7 and an aperture 5 is made and a wiring 6 is formed. As the forbidden band width is widen in the completed infrared detector region 8, the generation-recombination current in the surface region is small and reverse direction characteristics are improved. On the other hand, the incident light passes through the insulating film 7 and the semiconductor layer 2 with the wide forbidden band width and carriers are generated in a depletion layer produced near the bottom 4 of the layer 10, so that the sensitivity in the aimed long wave length band is improved. As the generation-recombination current is small, little noise is produced. And the output impedance is high enough to obtain high efficiency. |
