DEPLETION LAYER AND CAPACITANCE CALCULATIONS FOR GAUSSIAN DIFFUSED JUNCTIONS

Expressions are derived for the voltage dependence of the depletion layer width, the maximum electric field and the capacitance of Gaussian diffused plane, cylindrical and spherical p-n junctions. These are also shown in graphical form for junctions in silicon for a ratio of surface to background concentration covering the range 102-107. It is shown that the junctions can be considered to be either linearly graded or abrupt, depending on the voltage, with a transition range covering about 2 decades of voltage. Expressions are also given for the capacitance of rectangular and circular planar junctions and for an over depleted circular planar PIN diode. © 1969.