A charge-coupled device (CCD) image sensor is provided. The CCD image sensor may include an array of photosensors that transfer charge to multiple vertical CCD shift registers, which then in turn transfer the charge to a horizontal CCD shift register. The horizontal CCD shift register then feeds an output buffer circuit. The output buffer circuit can include multiple output stages, each of which can include a source-follower transistor coupled in series with a current sink transistor and at least one cascode transistor. The current sink transistor may have its gate terminal shorted to ground. In one arrangement, the cascode transistor has a gate terminal that receives a non-zero bias voltage. In another arrangement, the cascode transistor has a gate terminal that is also shorted to ground and operates in depletion mode.

A charge-coupled device (CCD) image sensor is provided. The CCD image sensor may include an array of photosensors that transfer charge to multiple vertical CCD shift registers, which then in turn transfer the charge to a horizontal CCD shift register. The horizontal CCD shift register then feeds an output buffer circuit. The output buffer circuit can include a load transistor implemented using a buried-channel drain (BCD) structure. The load transistor may include a gate conductor, a source diffusion region, a drain diffusion region, and a buried-channel drain region that at least partially extends under the gate conductor. The BCD region may be formed before or after the formation of the gate conductor. If desired, the BCD region can also be formed at the source edge. An image sensor configured in this way can exhibit higher source-drain breakdown voltages, enhanced amplifier gain, and reduced amplifier glow.

This solid-state imaging device 100 has: a photosensitive part that includes pixel portions 211, which are disposed in a matrix, and charge transfer parts 212 for transferring, by the column, the signal charge of the pixel portions; a plurality of charge storage parts 220 that accumulate the signal charges transferred by the plurality of charge transfer parts of the photosensitive part; a relay part 240 that relays the transfer of the signal charges transferred by the plurality of charge transfer parts to each charge storage part; an output part 230 that outputs the signal charges of the plurality of charge storage parts as electric signals; a first substrate 110 at which the photosensitive unit 210 is formed; and a second substrate 120 at which the charge storage part 220 and output unit 230 are formed. The first substrate and second substrate are stacked together, and the relay part 240 electrically couples the charge transfer parts of the first substrate to the charge storage parts of the second substrate by means of a connecting parts passing through the substrates outside the photosensitive region of the photosensitive part.