The Potential in a Charge-Coupled Device With No Mobile Minority Carriers

The Potential in a Charge-Coupled Device With No Mobile Minority Carriers By J. McKENNA and N. L. SCHRYER (Manuscript received May 17, 1973) The potentials and fields in a two-dimensional model of a chargecoupled device (CCD) are studied. We assume no mobile minority carriers have been injected into the CCD and that the electrode voltages do not vary with time. The nonlinear equations describing the devices are first linearized using the depletion layer approximation. The linearized equations are then solved approximately by a fitting technique. Both surface and buried channel CCD's are considered. The accuracy and cost of obtaining the solution is discussed. This work is a continuation of a study initiated in an earlier paper} In this paper we study the electrostatic potential distribution and fields in a two-dimensional model of a charge-coupled device 2,3 (CCD). This work is a continuation of a study initiated in an earlier paper 1 hereafter referred to as I. In I we considered a static, two-dimensional model with no mobile charge, and with electrodes so close together that they could be assumed to touch. We showed there that the depletion layer approximation 4 could be used to linearize the potential equations, and the linearized equations were then solved analytically. The numerical evaluation of these solutions was shown to be very accurate and cheap. We extend the model of I to allow for gaps between the plates. Our purpose here is twofold. We want to examine the dependence of the potentials and fields in a CCD on various design parameters.