| 摘要 |
PURPOSE:To enlarge the optical path length of a light absorption layer to optimize the utilization of applied light by forming pyramidal second semiconductor in regions free from mask materials. CONSTITUTION:An n-type GaAs layer is formed on a high concentration n-type GaAs substrate 1. In this case the GaAs substrate uses the (001) plane. Then pyramidal dots are formed thereon. For the purpose, an SiO2 film 11 is formed as mask for processing, and rectangular openings with their sides being of <110> and <-110> are formed by photolithography. Subsequently, the SiO2 film 11 is removed, and an n-type GaAs layer 3', p-type GaAs layer 4, p-type AlGaAs layer 5 and high concentration doping p-type GaAs layer 6 are deposited in this order. Then the high concentration doping p-type GaAs layer 6 is removed from the pyramidal parts by photolithography to form a p-type electrode 7, and an n-type electrode 8 is formed on the rear face of the substrate. This makes it possible to enlarge the optical path length in the light absorption layer. |
