Bucket-brigade device
It isn't so much that the capacitors are connected to the gates per se, but that they're connected to the clock signals.
The point is, the charge will flow from one capacitor to another only if the voltage on the first capacitor is higher. Only by raising the &quot;bottom&quot; of a capacitor to the highest system voltage during the high phase of its clock can you be sure of transferring all of its charge to the next capacitor.

The &quot;buffer&quot; transistors (the ones whose gates are connected to VGG) are actually there to make sure that charge transfers only in the forward direction, and that the capacitors never take on a negative voltage. Otherwise, the buckets would lose charge in both directions, and all you'd get out at the far end would be an average voltage for the whole chain.