Fabrication of submicron relief gratings in p-GaAs in the process of maskless holographic wet etching by laser-induced etch rate reduction method

Abstract

We report the masidess holographic fabrication of submicron relief diffraction gratings with periods 230-500 nm and depth-to-spacing ratio as high as 0.5 on the surface ofp-GaAs under visible laser light. The gratings were fabricated in the process of photochemical wet etching by laser-induced etch rate reduction method. The physical mechanism of laserinduced grating formation in p-type semiconductors is considered.

Photo-Dynamics of AlxGa1-xAs Heterostructure Dissolution: Experiments and Applications

“…The photo-assisted dissolution of semiconductors in aqueous solutions offers especially attractive possibilities in device fabrication (8)(9)(10); this is especially true for those without externally applied potential (i.e., electroless) since they are most compatible with the existing device technology. The photo-assisted dissolution has many possible applications such as control of the etched sidewall profile (1,7), maskless etching, selective etching and control of the etched side wall profile.…”

“…The literature suggests photo-dissolution models based on the Gerischer's band bending model [27, 31-35 (11, 15) for simple cases of bulk GaAs material (8) and GaAs/AlGaAs double layers (2) whereby photo-generated carriers control the dissolution. These models primarily focus on the dissolution rate and not on the surface condition and the sidewall angle variation for photo-assisted semiconductor dissolution.…”