The recombination lifetime &tgr;rhas been measured at low temperature in Sip‐channel metal oxide semiconductor field effect transistors (MOSFET’s) using the charge pumping technique. Measurements were performed over the 40–300‐K range. A monotonically increasing lifetime with decreasing temperature was measured. &tgr;rwas found to be proportional to exp(Ar/kT), whereAris a constant determined from the slope of ln &tgr; vs 1/T. For a typical MOSFET the lifetime ranged from 80 ns at 300 K to 370 &mgr;s at 100 K. The value ofArin this case was determined to be 106 meV.