Automatic lot organization method

Abstract

An apparatus for automatically organizing a variable number of lots into a batch which can be treated with high efficiency in a semiconductor wafer manufacturing line is installed for changing the number of lots organized into a batch between preceding and succeeding processes when such change is required. The apparatus includes a stocker array including a plurality of stockers disposed in a linear array and each capable of accommodating therein a plurality of lots, a first transfer robot disposed at one side of the stocker array for placing and taking out the lots in and from the stockers, a second transfer robot disposed at other side of the stocker array above for placing and taking out the lots in and from the stockers at a rear side thereof, a station for disposing thereon a plurality of lots handled by the first and second robots, a lot identifying device for reading identification information of the lots disposed on the station, a third transfer robot for transferring the lots disposed on the station with the first and second transfer robots, and a control unit for controlling automatically the stockers, the station and the first, second and third transfer robots in an coordinated manner to thereby allow the lots disposed on the station to be accommodated at predetermined positions in the stocker array in accordance with the lot identification information, to thereby organize the lots into a group in accordance with lot organization conditions such as conditions under which the lots are to be treated, distribution of load in the manufacturing line, and priorities allocated to the processes.