Nondestructive determination of p-n junction depth using laser beam induced current and lateral photovoltage measurements

A new technique is described in which the series resistance of laser beam induced current measurements can be determined. Once obtained, this resistance can be equated to an analytic expression for the resistance that involves the depth of the p-n junction in the illuminated photodiode, and a value for the junction depth can be obtained, as has previously been demonstrated. The new measurement scheme involves both laser beam induced current and lateral photovoltage measurements on the same device using the same remote contacts. This avoids the need for a contact to both sides of the p-n junction and hence the technique can readily be applied to individual photodiodes within a large focal plane array.