Understanding the Impact of Batch vs. Single Wafer in Thermal Processing Using Cost of Ownership Analysis

Conclusion

Thin film (</= 150Å) oxidation and BPSG densification appear to have approximately equivalent CoO values for the two types of systems. Unless oxide films become thinner (</= 40Å) or interfacial oxide control or silicon surface conditioning prior to oxidation become parameters of concern, both batch furnaces and single wafer systems are equally capable of the oxidation process. Metal sinter does not have an advantage in either CoO or technical capability in a single wafer system at this time. Both CVD polysilicon and nitride deposition have much higher CoO in RTP systems than in batch systems. Unless enabling technology requirements exist for these films, use of batch processing is recommended. Thin film RTCVD nitride may become comparable to batch processing as throughput, capital cost, and system maintenance issues are resolved.

This report does not attempt to address advantages of batch systems or single wafer systems where critical technical requirements exist for that process. Single wafer systems have an advantage over current batch systems in terms of thermal budget, film control, ambient control, temperature ramping, etc. which reduce the impact of CoO on the final decision. As batch systems transition to mini-batch fast ramp capability for 300mm, results of analyses may change.

CoO analysis is a useful technique for consideration of single wafer implementation over batch processing where enabling technology is not required.