Apparatus and method for enhanced degassing of semiconductor wafers for increased throughput

Abstract

A multi-level shelf degas station relying on at least two heaters integrated within wafer holding shelves or slots, where the semiconductor wafers do not have direct contact with the heater shelves. The heaters provide conduction heating. In order to degas a wafer, the heater and wafer holder assembly is positioned in a sequential manner through each wafer slot to the next available slot. If a degassed wafer exists in the slot, a transfer chamber arm removes it. A loader arm then places a wafer in the available, empty slot and the stage is moved upwards to receive the wafer from the loader arm. The transfer chamber arm removes an individual wafer from the heater and wafer holder assembly allowing the removed wafer to be individually processed while the other wafers remain in the heater and wafer holder assembly. In some instances, a loader arm may also remove wafers. The remaining wafers in the heater and wafer holder assembly are subjected to further degas treatment while the wafer(s) removed by the transfer chamber arm are exposed to other process steps. Air-cooling chambers are employed to facilitate cooling the wafer slots for ease of removal and maintenance.