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

Area of Science:

• Solid-state physics
• Semiconductor device engineering
• Image sensor technology

Background:

• Fully depleted charge-coupled devices (CCDs) require efficient output amplifiers for high-performance imaging.
• Existing amplifiers like floating diffusion and floating gate have limitations in speed and sensitivity.
• Novel amplifier designs are crucial for advancing CCD readout capabilities.

Purpose of the Study:

• To introduce a new output amplifier for fully depleted thick p-channel CCDs.
• To demonstrate the high sensitivity and nondestructive readout capabilities of the proposed amplifier.
• To compare the performance of the new amplifier against existing technologies.

Main Methods:

• Design and implementation of a double-gate MOSFET as a charge amplifier.
• Utilizing junction coupling between the CCD and MOSFET channels.
• Characterization of readout noise and readout speed in single and multi-sampling regimes.

Main Results:

• Achieved a readout noise of 0.74 e⁻rms/pix in single-pixel charge measurements.
• Demonstrated nondestructive readout capability.
• Attained 0.15 e⁻rms/pix with ten-sample averaging at a readout time of 2.74 ms, enabling single-electron/photon counting.
• Exhibited at least 6 times the speed of floating gate amplifiers.

Conclusions:

• The novel double-gate MOSFET amplifier provides superior performance for fully depleted CCDs.
• The amplifier enables high-sensitivity, fast, and nondestructive readout.
• This technology advances CCD imaging, particularly for applications requiring single-electron or single-photon detection.