METHOD FOR ETCHING SUBSTRATES COMPRISING A THIN SURFACE LAYER, FOR IMPROVING THE UNIFORMITY OF THICKNESS OF SAID LAYER

• Main Authors: CARTON, Sébastien, VIRAVAUX, Laurent, ROS, Onintza
• Format: Patent
• Language: English; French; German
• Published: 26.10.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A method for etching a main surface of a thin layer of a substrate, which comprises immersing the substrate in an etching bath so as to expose the main surface to an etching agent, the substrate being oriented relative to the bath such that:-when it is introduced into the bath, the main surface is gradually immersed from an initial introduction point (PII) to an end introduction point (PFI), at an introduction speed, and-when it exits the bath, the main surface gradually emerges from an initial exit point (PIS) to an end exit point (PFS), at an exit speed, the method being characterized in that:-the introduction speed is chosen in such a way as to etch the main surface according to a first non-uniform profile between the initial introduction point (PII) and the end introduction point (PFI), and/or-the exit speed is chosen in such a way as to etch the main surface according to a second non-uniform profile between the initial exit point (PIS) and the end exit point (PFS), in order to compensate for non-uniformities in the thickness of the thin layer.