This is the difference between an etching machine and a lithograph machine
The simplest difference is that the lithography machine projects the circuit diagram onto the silicon wafer covered with photoresist, and the etching machine then corrodes the excess circuit diagram on the silicon wafer where the circuit diagram was just drawn, which is the difficulty of this lithography and etching.
The process of photolithography is to coat the surface of the silicon circle with a layer of photoresist, and then shine light through the mask to the surface of the silicon circle. Because of the cover of the photoresist, the irradiated part is corroded, and the part without light is left, which is the required circuit structure.
Etching is the circuit structure, dry engraving has not yet achieved commercial mass production, the principle is to use plasma instead of chemical solution, remove the unwanted silicon circle part.
The difference is etching and lithography, etching is the need for an etching agent, the etching agent is a etching agent, lithography is the use of laser engraving.