Modification of time dependence in thermal wave signal from ion implanted wafers

The thermal wave signal from ion implanted silicon wafers exhibits gradual change as a function of time after implant. This change in thermal wave signal can affect the long term repeatability of measurements made on implant monitors. This paper describes a method for reducing, and in many cases eliminating, the time dependence of the thermal wave signal. Wafers implanted with B ⁺, P ⁺, and As ⁺ at doses ranging from 10 ¹¹ to 10 ¹⁴ ions/cm ² and energies from 60-100 keV were subjected to l temperature anneals for varying times. The decay factor was studied as a function of anneal temperature and time. The effect of exposure of the wafers to UV radiation is also discussed.