Joannes Joseph Maria Koomen

Punch-through currents in P+NP+ and N+PN+ sandwich structures—I: Introduction and basic calculations

Abstract A qualitative description and a quantitative approximation of the current/voltage characteristic of the punch-through effect, based on drift- and diffusion-theory, is presented. An exact definition of the punch-through voltage is given. For small currents the current/voltage characteristic of the punch-through effect is an exponential curve i = I 0 exp [ q ( V − V PT )/ m ( i ) kT ] where m ( i ) is a non-ideality factor which is equal or larger than 2 and which increases with increasing current. At larger currents a deviation of the exponential curve is found due to space-charge limiting effects. A more general theory for small currents and some experimental verifications are described in Part II[48].

Punch-through currents in P+NP+ and N+PN+ sandwich structures—II: General low-injection theory and measurements

Abstract Analytical one-dimensional exponential expressions are derived for the current/voltage characteristics of the punch-through effect in devices where a certain bias voltage is needed to bring the device into punch-through ( V PT > 0) and where punch-through is already present in the non-biased condition ( V PT = 0). Measurements show that the theory can describe the current/voltage relations adequately at low current levels.