Achieving Single-Electron Sensitivity at Enhanced Speed in Fully Depleted CCDs with Double-Gate MOSFETs.

We introduce a new output amplifier for fully depleted thick p-channel CCDs based on double-gate MOSFETs. The charge amplifier is an n-type MOSFET specifically designed and operated to couple the fully depleted CCD with high charge-transfer efficiency. The junction coupling between the CCD and MOSFET channels has enabled high sensitivity, demonstrating readout noise of 0.74  e_{rms}^{-}/pix in one pixel charge measurement. We have also demonstrated the nondestructive readout capability of the device. Single-electron and single-photon per pixel counting in the entire CCD pixel array has been made possible through the averaging of ten samples, achieving 0.15  e_{rms}^{-}/pix in a pixel readout time of 2.74 ms. We have demonstrated fully depleted CCD readout with better performance than the floating diffusion and floating gate amplifiers available today, in both single and multisampling regimes, boasting at least 6 times the speed of floating gate amplifiers.