RESUMO
A custom CMOS image sensor hardened by design is characterized in a transmission electron microscope, with the aim to extract basic parameters such as the quantum efficiency, the modulation transfer function and finally the detective quantum efficiency. In parallel, a new methodology based on the combination of Monte Carlo simulation of electron distributions and TCAD simulations is proposed and performed on the same detector, and for the first time the basic parameters of a direct CMOS electron detector are extracted thanks to the TCAD. The methodology is validated by means of the comparison between experimental and simulation results. This simulation method may be used for the development of future electron detectors.
RESUMO
Controlling two dimensional doping distributions is an important benefit in order to check processed substrates or specific devices. To achieve this purpose, a new methodology is proposed in order to obtain qualitative maps of acceptor concentration from one EBIC image. Analytical models are used to help in defining the best experimental condition and to check the validity of the approach, and a TCAD simulation is performed on a realistic structure and shows promising results. Then, a measurement is carried out on a device and the epitaxy gradient is clearly visible, as well as the presence of Pwell layers.
RESUMO
A novel method is presented with the aim to perform minority carrier diffusion length map on cross-sectional samples. The method is based on one Electron-Beam Induced Current (EBIC) acquisition and on the analyze of the EBIC signal slope variation on each scanned points. This method is applied on a pinned photodiode array realized on a low doped silicon epitaxy, and the electron diffusion length map which is extracted is in good accordance with our expectation taking into account the doping distribution of the device. A TCAD simulation also confirms quantitatively the measured diffusion length map. Advantages and drawbacks of this method are discussed in this study.
