(color online) Front-gate transfer characteristic curves of the PDSOI nMOSFETs with W/L = 10 μm/0.35 μm (a) under ON bias and (b) under PG bias. The “front first” means that front-gate curves of samples from group-front are first measured, and the “back first” means that back-gate curves of samples from group-back are first measured. The “first test” and the “second test” mean the curves are measured the first time and the second time, respectively. These legends hold true for the following figures.