Microwave Heating for VLSI Processing

Rapid Thermal Processing (RTP) will be necessary to meet the limited temperature budget in submicron VLSI manufacturing. In this paper we present a reactor concept for LPCVD and other thermal processes, utilizing microwave energy to heat silicon wafers to the required temperature. The reactor, in the form of a single mode microwave cavity allows us to uniformly heat a 100 mm silicon wafer in the temperature range 300 to 450°C with a temperature variation of less then +/- 5°C and in the range 450 to 1000°C with about +/- 10°C variation across the wafer. This paper presents the principle of microwave heating and experimental results on some process steps like selective and blanket tungsten deposition, in situ plasma cleaning, dopant activation, silicide formation and curing processes.