Hello, my name is Adrian and I work here in the Etch area.
We remove some of a layer from the wafer surface to create a permanent pattern in the silicon.
The wafers with the temporary pattern on them are introduced into the etch tools. These tools use acids or plasma gases to remove parts of the wafer surface. All of the exposed area of the wafer i.e. all areas which are not protected with photoresist are removed - this creates a permanent pattern in the layer below. Once etching is complete, the temporary photoresist pattern is removed and we clean the wafers. The wafers are now ready for a new layer to be deposited and patterned. The wafers will pass between all these areas many times, building up the transistors and the metal lines. After all this work is completed we send the wafers to E-Test and Sort to test and sort the die .
