How Does the Shift of Charge Occur in CCDs?

[Ngineer]

Hello everybody,

All resources I found online about CCDs, state that they shift charge one step at a time.
How does this shift take place?

Thanks

 

[carlgrace]

Basically they make a deep potential well under the pixel that has the charge that you want moved. They do this (assuming an n-type substrate) by applying a large voltage to the gate above the pixel. This biases the MOS capacitor that defines the pixel into deep depletion.

Next, the target pixel (where you want the charge to go) is also biased into deep depletion. Then, you turn off the large voltage to the first pixel but keep it on for the second pixel. Then the charge moves into the second pixel.

This is repeated over and over again until the charge reaches the output stage of the CCD.

 

[Ngineer]

This clears things. Thanks a lot