In response to the high resolution requirements of EBAPS digital low light imaging devices in military and aerospace fields, the spatial modulation transfer function is an objective method to evaluate the resolution of liner photoelectric imaging system. on the basis of the existing GaAs photocathode and CMOS structure, a five-part MTF model of EBAPS devices were constructed using modulation transfer function theory. It was proposed that the electron dispersion and scattering characteristics during electron transmission are the main factors causing the decrease in resolution. We studied the dispersion characteristics of near-field photoelectrons based on the physical model of near-field focusing. Based on the theory of low energy electron solid interaction, we combined Monte Carlo simulation methods to derive and simulate the electron transit and scattering characteristics of the passivation layer. Based on the theory of electron diffusion and drift in semiconductors, We constructed a CMOS electron transport model to analyze the electron transport diffusion characteristics. Finally, the electron dispersion and scattering mechanism of EBAPS is revealed, and the MTF model of EBAPS is established, which is composed of near-field dispersion, CMOS transport diffusion and CMOS chip. Moreover, by optimizing the proximity process parameters to realize the device preparation, the ultimate resolution of EBAPS was increased from 22lp/mm to 32lp/mm. It is pointed out that backscatter dispersion of incident electrons on the CMOS surface is a key method to further improve resolution. This has important guiding significance for the future development of high-resolution EBAPS devices.
Heat cleaning is one of the most widely used methods for preparing GaAs photocathode. The GaAs photocathode obtained by heat cleaning can obtain high sensitivity. The temperature, stress and strain of GaAs photocathode during heat cleaning significantly affect the activation sensitivity and resolution. However, it is very difficult to accurately measure the temperature, stress and strain of GaAs photocathode during heat cleaning. Therefore, it is of great significance to simulate the temperature, stress and strain of GaAs photocathode during heat cleaning. In this study, the mathematical models of GaAs photocathode, glass, fixture and heating apparatus during heat cleaning were developed. Then, coupled with thermal radiation and heat conduction, the transient temperature distributions of GaAs photocathode, glass, fixture and heating apparatus during heat cleaning were obtained. Finally, the stress and strain of photocathode, glass, and fixture were investigated by coupling heat transfer and mechanical properties.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.