Effect of the energy of ion-chemical etching of GaAs/AlxGa1-xAs structures on photoluminescence and degradation of devices

The process of ion-chemical etching of mesa-stripes in epitaxial GaAs/Al_xGa_1-xAs structures on a setup with an inductively coupled plasma source is studied. The advantage of the setup is a high plasma density in the etching area and, therefore, a low ion energy (100—200 eV), which can be varied independently of the RF power. The process is developed for forming narrow (3–5 μm) mesa-stripes with a side-wall tilt of ~85° and the scatter in the values of geometrical parameters equal to ±1% in the etching area of diameter 150 mm. It is shown that, unlike RF etching, the decrease in the photoluminescence intensity in GaAs/Al_xGa_1-xAs structures is stabilised at the 15%–20% level of the initial intensity even when the etching area is located only at a distance of 100–150 Å from the active region. Comparative tests are performed for ridge superluminescent diodes manufactured by using RF radiation sources and inductively coupled plasma.