Micro-device having a metal-semiconductor compound layer protected against HF etching and method for making the same

A method for making a micro-device, during which at least one first element of the micro-device is made, the method comprising:

• making, on a substrate, a stack of a first layer and of two second layers such that the first layer is arranged between the two second layers, that the first layer includes at least one metal, that one of the two second layers comprises at least one first material able to withstand an HF etching, that the other of the two second layers comprises at least one second material able to withstand the HF etching, and that at least one of the first and second materials able to withstand HF etching includes a semi-conductor;
• heat treating, such that a part of the semi-conductor reacts with the metal to form a layer of material consisting of a compound of the semi-conductor and the metal, and such that at least one remaining part of each of the two second layers form first and second protective layers each directly contacting two opposite faces of said layer of material and such that the first and second protective layers are not in direct contact with each other at all points above the substrate;
• and further comprising implementing a step of HF etching during which said layer of material is protected from HF by the first and second protective layers.