A dual arm robot for a substrate processing system includes a base and a first arm having extended and retracted positions. Each of the first and second arms includes a first arm portion having one end rotatably connected to the base, a second arm portion having one end rotatably connected to another end of the first arm portion, and an end effector having one end rotatably connected to another end of the second arm portion and another end configured to support first and second substrates, respectively. When the first and second arms are arranged in the retracted position, connections between the second arm portions and the end effectors are located over or under the second and first substrates, respectively, and the first substrate is not located over or under the second substrate.