| 摘要 |
PURPOSE:To reduce the loss and size of the semiconductor optical switch by controlling the forbidden band width of a quantum well by changing surface passivation conditions. CONSTITUTION:An n-Al0.3Ga0.7As clad layer 2, a multiple quantum well MQW waveguide layer 3, an undoped Al0.3Ga0.7As clad layer 4, and an undoped GaAs contact layer 5 are grown in order on an n<+>-GaAs substrate 1 by molecular beam epitaxy MBE to form a layer structure. Then a Zn diffused area 6, a nonimpurity and disorder area 7A formed by changing the passivation conditions in a heat treatment is formed and an SiO2 layer 9 is adhered on the entire surface of the substrate; and the SiO2 layer 9 in the Zn diffused area 6 is opened and a p-side electrode 10 and an n-side electrode 11 on the reverse surface of the substrate 1 are formed. The Zn diffused area 6 is made into a p-type with high density up to right above the MQW3 to form a PIN structure across the MQW3. On the other hand, the MQW3 of the nonimpurity and disorder area 7A increases in forbidden band width and the MQW3 surrounded with this area forms two crossing waveguides 8. Consequently, the loss and size are reduced. |
