Enhanced Equipment and New Processes As Enabler for Power Technologies on 300mm Substrates

Abstract

The customized substrates for manufacturing 300mm power semiconductors had to be prepared by deposition processes and epitaxial growth on standard substrates since they were not yet available from suppliers in both sufficient quality and quantity. Polysilicon films were deposited on wafer backsides and optimized regarding impurity gettering. Severe modifications of existing epitaxy reactors, the facilitation, and the infrastructure were prerequisite to develop extremely high doped, thick silicon layers with both supreme uniformity of layer thickness and dopant distribution to take full advantage of the productivity advantage of large diameter wafer processing. Simulation supporting these activities was also key to enable furnace processes with extremely tight temperature ranges. For the development of very thick, high resistivity silicon layers a 5-wafer 200mm batch tool was used to exploit the tool and process learning for the design and manufacturing of a similar 300mm batch tool. For pattern transfer the same advanced plasma etch equipment was mandatory to achieve similarly uniformities regarding etch rate, profile shape, and CD as in CD-driven advanced DRAMs and MPUs.