Abstract This paper describes a custom built, limited reaction processor developed to allow sequential in-situ processes such as plasma clean, plasma oxidation and chemical vapour deposition. The reactor uses tungsten-halogen lamps to heat the wafer up to 1000°C with a maximum rate of 200°C s −1 . A microwave magnetron provides gas plasma generation capability. It is shown that wafer temperature is a function of silicon type and dopant concentration. Polysilicon layers produced by the system are incorporated into polysilicon emitter bipolar transistor. Devices fabricated using a sequential in-situ plasma-clean, plasma-oxidation polysilicon deposition schedule exhibit more uniform gains compared to those devices given a wet-etch dip prior to polysilicon deposition.