Sensor with electrically controllable aperture for inspection and metrology systems

A sensor comprising:

• a substrate having an upper surface and an opposing lower surface;
• a plurality of pixels disposed on the substrate, each pixel including a resistive control gate attached to the upper surface and disposed over an associated light sensitive region of the substrate, and at least one transfer gate disposed adjacent to a first end portion of said resistive control gate;
• a plurality of elongated aperture control electrodes extending in parallel across said resistive control gates of said plurality of pixels, said plurality of aperture control electrodes including a first end electrode contacting said first end portion of each said resistive control gate, a second end electrode contacting a second end portion of each said resistive control gate, and one or more central electrode contacting each said resistive control gate and disposed between said first and second end electrodes;
• and
• a control circuit configured to simultaneously apply aperture control signals onto said resistive control gates of said plurality of pixels by way of said plurality of aperture control electrodes such that first and second aperture control signals applied to said first and second end electrodes are more positive than a third aperture control signal applied to said at least one central electrode, thereby causing each said resistive control gate to generate an electric field in said associated light sensitive region such that first photoelectrons generated by said first light portions in a first light sensitive portion of each said pixel are driven by said electric field into a first charge accumulation region located adjacent to said first end portion of each said resistive control gate, and such that second photoelectrons generated by second light portions in said second light sensitive portion of each said pixel are driven by said electric field toward said second end portion of each said resistive control gate.

A system for inspecting or measuring a sample, the system comprising:

• an illumination source configured to generate light;
• optics configured to direct said light from the illumination source to the sample, and to direct light from the sample to a sensor;
• a sensor including:
• a substrate having an upper surface and an opposing lower surface;
• a plurality of pixels disposed on the substrate, each pixel including a resistive control gate attached to the upper surface and disposed over an associated light sensitive region of the substrate;
• at least three aperture control electrodes extending across and electrically connected to said resistive control gate of each of said plurality of pixels, said at least three aperture control electrodes including first and second end electrodes respectively extending across opposing first and second end portions of each said resistive control gate, and one or more central electrode disposed between said first and second end electrodes;
• a control circuit configured to simultaneously apply aperture control signals onto said resistive control gates of said plurality of pixels by way of said at least three aperture control electrodes such that each said resistive control gate generates an electric field in said associated light sensitive region that separates photoelectrons generated by light entering the associated light sensitive region into at least two portions;
• and
• at least one readout circuit disposed on at least one side of the plurality of pixels.