A wafer processor has a rotor holding wafers within a process tank. The rotor rotates sequentially moving the wafers through a process liquid held in the process tank. The tank may have an I-beam shape to reduce the volume of process liquid. A load port is provided at a top of the process tank for loading and unloading wafers into and out of the process tank. Rinsing and cleaning chambers may be associated with the load port to remove process liquid from processed wafers. The processor may be oriented with the rotor rotating about a horizontal axis or about a vertical axis.