Origin of Initial Rapid Cell Current Reduction in Non-Volatile One-Time Programming Memory

The fast bit cell current (BCC) reduction in a one-time programming (OTP) device during high-temperature annealing will severely decrease the data retention (DR) capability. It is found that negative bias temperature instability-like degradation is responsible for this fast BCC shift, which is different from the well-known DR mechanism. The rapid floating gate charge diminution at the initial stage can be attributed to the recombination by hydrogen species as a result of the depassivation of Si-H bonds at the Si/SiO
₂
interface. Our experiments show that the BCC reduction rate follows a power-law time dependence t
^-0.73
, which is in agreement with a simple analytical model based on interface state (N
_it
) generation and floating-gate voltage shift. These observations pave the way for further OTP DR reliability improvement.