Determination of electron depth-dose function for kilovolt electrons on GaAsP

Abstract

A new technique to determine the depth-dose function is described using the measurement of the electron beam induced barrier current on bevelled homo p-n junction structures. A universal depth-dose function on GaAsP is found in the form \documentclass{article}\pagestyle{empty}\begin{document}$ \Phi (z)\, = \,\Phi _0 \,\exp \,\left[{ - \left({\frac{{z - a}}{{z_0 }}} \right)^2} \right]\,{\rm with}\,z_0 \, = \,\left\{{\begin{array}{*{20}c} {2.3a\,{\rm for}\,z \mathbin{\lower.3ex\hbox{$\buildrel>\over {\smash{\scriptstyle=}\vphantom{_x}}$}} a} \hfill \\ {1.3a\,{\rm for}\,0 \mathbin{\lower.3ex\hbox{$\buildrel<\over {\smash{\scriptstyle=}\vphantom{_x}}$}} \,z\, < \,a} \hfill \\ \end{array}} \right. $\end{document} in the investigated energy range from 10 to 45 keV. The distance of the maximum under the surface can be obtained by the relation a = A0EPr1.65 with A0 = 2.95 × 10−3 (EPr in keV, a in μm).