The accelerated photoelectrons that produce the electron-hole pairs in the CCD also produce soft X-rays as they bombard the silicon. Although the kilovolt electrons incident on the CCD's back surface do not travel far enough into the silicon to affect the front surface gate structures (see Figure 4), the gate insulator may absorb the X-rays and cause the production of fixed charge in that region as well as 'trapping' states at the Si-SiO₂ interface. Damage to the gate structure oxide layers from keV level X-rays will likely result in increased dark current and decreased full-well capacity. The intensity and dose of the X-rays produced in the CCD are proportional to the number of incident electrons and their accelerating energies. Because of the X-ray's dependency on the incident electron's energy, a reduction in the accelerating potential will minimize the intensity of the X-rays produced. However, reducing the accelerating potential also decreases the sensor's gain and contrast resolution. Similarly, as X-rays produced further from the gate structure have lower probability of traveling to the gate structures, increasing the back surface's thickness will result in fewer X-rays reaching the front surface. Albeit, at the expense of contrast resolution.

As Multi-pinned phase (MPP) CCDs operate in an 'inverted' mode, they are less susceptible to the effects of ionizing radiation than are standard modes of CCD operation . Operating a CCD in MPP mode does somewhat compromises the pixel's capacity to hold charge. Using accelerating voltages below 1.8 keV (K-alpha X-ray producing energy in silicon), using radiation compatible gate dialectrics, and using an MPP operating mode will minimize the effects of radiation damage in the electron bombarded CCD.

To determine the increase in CCD dark current attributable to high energy electron bombardment, a SITe model SI502AB CCD, thinned to a less than a 15 micron epitaxial thickness, was tested in a Hitachi model S4000 scanning electron microscope. Using a 1*10^-2 C/cm² electron dose, the experiment varied the electron accelerating energies incident on the back-illuminated CCD and measured the resulting increase in CCD dark current. Figure 14 shows the increase in dark current versus incident electron energies. Shown on the graph's right y-axis is the sensor's relative lifetime operating with a 1*10^-4 footcandle faceplate illumination. The back-thinned CCD's 'lifetime' is defined, herein, to be a 50 electron per pixel increase in CCD dark current per 16.7 millisecond integration period. A 50 electron increase in dark current will result in low light performance limited by the dark current shot noise and not the readout noise and will thus begin to degrade contrast and sensitivity. The experiment demonstrated that at accelerating voltages below 1.8 keV, the lifetime of both MPP and non-MPP CCDs will exceed the operation life of military Gen-III image intensified tubes, which is typically specified at 16,000 hours.

Gallium arsenide photocathodes are particularly susceptible to contamination from residual gases within the tube. Not having to use an MCP for gain removes over 0.240 square meters of surface area from the image tube vacuum. The SI502AB used in the EBCCD sensor has only 0.00015 square meters of active surface area. Since the EBCCD image tube has a relatively small volume compared to traditional image intensified tubes and does not have the MCP's surface area to contend with, the EBCCD's photocathode will have a far longer lifetime. Optimization and characterization of the EBCCD's lifetime will be an area of continuing research.

Furthermore, the EBCCD's back surface thinning process must be compatible with high temperature semiconductor processing. As organic materials degrade image tube lifetime, the adhesive used in the back-illuminated CCD's supporting structure must contain no organic materials. Until recently, these requirements have limited the maturation of thinned, back-illuminated CCDs for EBCCD applications.

The EBCCD image tube is inherently easier to process than standard image tubes. Because it does not require a microchannel plate, a phosphor screen, or fiberoptics, the device is very simple to manufacture. In addition to the pure material costs, the manufacturing tolerances required for the spacing between these components increases the complexity and the cost of manufacturing conventional, image tube ICCDs.