Random telegraph signal (RTS) measurements have been used to study individual hot-carrier-induced trap in nMOSFET's. Single-trap filling and emptying can cause 0.1% step noise in channel current. Trap location (3-10 angstrom from interface), time constant (approximately 10 ms), and energy are found to be quite different from those of prestress (process-induced) traps. The type (acceptor or donor) of the traps can also be identified by RTS measurements; both the process and stress-induced traps with energies near the conduction band edge are found to be of the acceptor type for nMOSFET's and trap levels near the valence band edge are found to be of the donor type for pMOSFET's.