Front-end, single-wafer diffusion processing for advanced 300-mm fabrication lines

Single-wafer, diffusion processing offers the possibility to significantly reduce cycle times, provide ‘greener’ processes and fulfil key technology requirements of ever-reducing thermal budgets and improving critical thin-film interface control. This paper will discuss the cycle time and other potential gains of a transition to 300-mm single-wafer diffusion processing and go on to describe work carried out on such processing for advanced nitride CMOS gate and SiGe applications. Multi-product, multi-process ASIC/SOC 300-mm processing will require aggressive cycle times to ensure early time-to-market, rapid time-to-volume and accelerated development of new technologies and functionality. One of the key cycle time detractors in current multi-process facilities is the batching requirement in diffusion. The advantages of a transition to single-wafer diffusion processing will be presented. A nitrided CMOS gate application has been studied on a 300-mm single-wafer tool featuring a module for RTA/RTO/RTN, a module for mono-Si/poly-Si and SiGe CVD deposition and a cool-down chamber equipped with optical metrology to allow direct control of different steps. Different pre- and post-nitridation steps on oxide or oxide-free silicon surface will be reported that demonstrates the advantages of such an integrated single-wafer tool.