A semiconductor device may include a semiconductor substrate with first and second spaced apart source/drain regions defining a channel region therebetween and a control gate structure on the channel region between the first and second spaced apart source/drain regions. More particularly, the control gate structure may include a first gate electrode on the channel region adjacent the first source/drain region, and a second gate electrode on the channel region adjacent the second source/drain region. Moreover, the first and second gate electrodes may be electrically isolated. Related devices, structures, methods of operation, and methods of fabrication are also discussed.