Silicon wafer transportation system

A wafer transfer system for use in a photolithography system comprising a wafer storage apparatus, a pre-alignment apparatus, a buffer stage and a wafer stage, wherein the wafer transfer system comprises:

• a dual-arm robot comprising a main body as well as a wafer loading arm and a wafer unloading arm both in movable connection with the main body, wherein the wafer loading arm is configured to take a wafer to be exposed from the wafer storage apparatus and transfer the wafer to be exposed onto the pre-alignment apparatus, the wafer unloading arm is configured to remove an exposed wafer from the buffer stage and place the exposed wafer back into the wafer storage apparatus;
• a wafer-loading linear robot, configured to transfer a pre-aligned wafer onto the wafer stage;
• and
• a wafer-unloading linear robot, configured to transfer the exposed wafer onto the buffer stage;
• wherein each of the wafer-loading linear robot and the wafer-unloading linear robot comprises a fork, a linear motor and a slider, the linear motor comprises a linear motor stator, a slide rail and a linear motor mover, the slide rail is provided on the linear motor stator, the linear motor mover is configured to drive the slider, and hence the fork moves along the slide rail;
• and
• wherein at least two dual-arm robots, the wafer-loading linear robot and the wafer-unloading linear robot operate in parallel.