THERMAL PROCESSING: SHRINKING DEVICES ON LARGER WAFERS

摘要

Frontend transistor fabrication steps include thermal oxidations, nitridations, ion implantation anneals and silicide formation steps as well as the low-pressure chemical vapor deposition (LPCVD) of polysilicon, nitride and oxide films. Because transistor dimensions continue to decrease, there is unprecedented demand for process temperature and layer thickness uniformity and repeatability. Small variations in the critical gate oxide thickness or deviations in the source/drain junction depths, for example, can cause unacceptable device and circuit performance variations.