Abstract
The concentrations of etchant solution substituents in metal assisted chemical etching (MACE) processes control the morphology and reflectivity of subsequently etched wafers. In particular, the concentration of hydrogen peroxide (H2O2) plays a vital role in the MACE process. Unfortunately, the H2O2 concentration is not stable when prolonging the etching process at higher temperatures. As a result, the commercialization of MACE processes for the production of IP texturization has appeared industrially unattractive. Herein, we proposed an innovative method to monitor hydrogen peroxide during the MACE process with an electrochemical method. Reduced graphene oxide (RGO) prepared through an environmentally benign electrochemical method was used to modify a screen-printed electrode (SPE). Under an optimized condition, the RGO/SPE was used to test etching solutions. The MACE process was conducted and the hydrogen peroxide concentration within the etching solution was checked by the RGO/SPE. The RGO/SPE demonstrated excellent electrochemical performance and could record changes to H2O2 concentrations with cyclic voltammetry (CV). Interestingly, the presence of copper (Cu) in the etching solution catalyzed not only the etching process, but also the electrochemical reduction of H2O2. After etching, the reflectivity and structural morphology of the etched wafers were checked. The described modified electrode is disposable, and the fabrication process is rapid and inexpensive, allowing for real time application in, and control of, MACE processes.
The wettability between etching solutions and the surface of multicrystalline silicon wafer during metal-assisted chemical etching process
