| 摘要 |
PURPOSE:To regulate the thickness of an activation layer with ease during manufacture by a method wherein the activation layer is not exposed to etching and is epitaxially grown on a flat surface of a substrate. CONSTITUTION:On an n<+>-GaAs substrate 1, a carrier confining layer 2 composed of n-AlGaAs, undoped AlGaAs activation layer 3, carrier confining layer 4 of p-AlGaAs, are epitaxially grown in that order, whereafter a mesa stripe 4a is built by the photolithography method. A process follows wherein an n-GaAs light absorbing layer 5 is epitaxially grown on the carrier confining layer 4, an SiO2 insulating film 11 is attached to the light absorbing layer 5, portions located just on the mesa stripe 4a are removed. Finally, a p type diffused region 5a, a p-side electrode 12 of Cr/Au, an n-side electrode 10 of Au-Sn are provided. With the device being constructed as such, the activation layer 3 is approximately 500Angstrom thick, the carrier confining layers 2, 4 are both 1.5mum thick, and the light absorbing layer 5 is 1mum thick. The thickness of a portion 4b retained after etching turns out to be 0.2mum, which is adequately small in comparison to the spread thickness-wise of the light waves propagating through the activation layer 3. |
