Electron Multiplying Low-Voltage CCD With Increased Gain

Novel designs for the gain elements in electron multiplying (EM) charge-coupled devices (CCDs) have been implemented in a device manufactured in a low-voltage CMOS process. Derived with help from TCAD simulations, the designs employ modified gate geometries in order to significantly increase the EM gain over traditional structures. Two new EM elements have been demonstrated with an order of magnitude higher gain than the typical rectangular gate designs, achieved over 100 amplifying stages and without an increase in the electric field. The principles presented in this paper can be used in CMOS and CCD imagers employing electron multiplication in order to boost the gain and reduce undesirable effects such as clock-induced charge generation and gain aging.