The same total dose can produce a different conclusion under a different bias condition
A TID test is not complete when a sample reaches a target dose. Electric field, operating state and measurement timing all influence charge transport, trapping and the parameter drift that is ultimately observed.
Bias belongs at the same configuration level as dose and dose rate. Without DUT mapping, setpoint and measured values, current limiting, duty cycle and interruption records, execution drift can be mistaken for device response.
Bias changes the internal electric field, not just the report format
For MOS structures, radiation-generated carriers separate, move and become trapped under the internal field. Positive bias, negative bias, off-state storage, dynamic operation and unbiased storage can therefore produce different oxide-field and carrier-transport conditions.
A controlled bias configuration should include
DUT-to-channel mapping
Record device identity, pins, channel, polarity, grounding and current-limit conditions.
Setpoint and measured value
Software settings alone do not prove that the intended bias reached the sample.
Operating state and duty cycle
Static, off-state, switching and functional modes represent different electrical stress states.
Measurement timing
Irradiation interruption, bias switching, transfer time and annealing conditions can change the observed result.
A trend observed for one process, batch, package, dose and bias condition cannot be generalized without controlled samples and comparison groups.
PROJECT INTAKE
Turn the topic into a controlled test question
Submit a non-sensitive device category, objective, target dose, bias conditions and schedule for initial review.