METHOD FOR FORMING A BACK-TO-BACK WAFER BATCH TO BE POSITIONED IN A PROCESS BOOT, AND HANDLING SYSTEM FOR FORMING THE BTB WAFER BATCH

摘要

The invention relates to methods and a handling system for forming stacks of wafers which need to be doped on one side, in particular solar wafers which need to be doped on one side, for the purpose of filling a process boot with wafer batches, in which a predetermined even number of wafers are provided in rows in the accommodating slots of a transfer carrier which is to be clamped on a horizontal plane and has a stacking opening which points upwards. In order to increase the packing density in the process boot and thus to increase the throughput of the diffusion process, half of the number of wafers provided in rows in the transfer carrier are transferred, in the form of a first wafer stack, from the transfer carrier to a position of readiness held outside the transfer carrier, the other half of the number of wafers provided in rows in the transfer carrier are then moved, in the form of a second wafer stack, out of the transfer carrier and the second wafer stack is pivoted in such a manner that the wafers in the second wafer stack pass into a position that has been pivoted through 180° relative to the position of the wafers in the first wafer stack in the position of readiness thereof, and the second wafer stack is then transferred to the position of readiness of the first wafer stack, is oriented with respect to the latter and is then joined to the first wafer stack in a positively locking manner to form a packet-type back-to-back wafer batch (BTB wafer batch) by virtue of those sides of the associated wafers in the first and second wafer stacks which do not need to be doped respectively being simultaneously placed on top of one another in a congruent manner, whereupon the BTB wafer batch is accepted by a transfer gripper in a positively locking manner and is loaded into the process boot.