Rk. Reich et al., INTEGRATED ELECTRONIC SHUTTER FOR BACK-ILLUMINATED CHARGE-COUPLED-DEVICES, I.E.E.E. transactions on electron devices, 40(7), 1993, pp. 1231-1237
A novel electronic shutter has been integrated into the structure of a
back-illuminated frame-transfer charge-coupled device (CCD) to permit
short optical exposure times and to reduce the smear that occurs duri
ng the transfer of an image from the CCD detection area. The shutter c
onsists of an n+ shutter drain placed in the vertical channel stop reg
ions and stepped p-type buried layers formed by a high-energy implanta
tion (1.0-1.5 MeV) located between CCD n-type buried channel and p- su
bstrate. These structures create electric fields that direct the photo
electrons to either the CCD detection region or the n+ shutter drain.
The ratio of photons detected with the shutter open to photons detecte
d with the shutter closed has been measured to be greater than 75 000
for wavelengths below 540 nm. The corresponding shutter rise and fall
times are less than 55 ns.