Method for determining photodiode performance parameters

Abstract

One or more photodiode performance parameters for a photodiode are determined by first determining four data points Iph1, Voc1, Iph2, and Voc2, where Iph1 is a first short-circuit current, and Voc1 is a first open-circuit voltage, for the photodiode under a first illumination condition, and Iph2 is a second short-circuit current, and Voc2 is a second open-circuit voltage, for the photodiode under a second illumination condition. Then, at least one photodiode performance parameter for the photodiode is determined as a function of said four data points.

Description

BACKGROUND OF THE INVENTION[0001] 1. Field of the Invention[0002] This invention pertains to methods for manufacturing and testing semiconductor photodetector devices and, in particular, to methods for determining photodiode performance parameters including the dynamic impedance-area product R.sub.0A, the external quantum efficiency .eta., the specific detectivity D*, and other photodiode performance parameters.[0003] 2. Description of the Related Art[0004] The following descriptions and examples are not admitted to be prior art by virtue of their inclusion within this section.[0005] It is desirable to employ photodetectors to convert electromagnetic radiation, such as infrared (IR) radiation, into electrical signals. Such photodetectors may be used in a variety of applications, including thermal imaging and transmission of information using signals having infrared wavelengths. One type of photodetector is the junction photodetector, or photodiode, which has a semiconductor p-n junc...

AI Technical Summary

Benefits of technology

0028] FIG. 2 is a plot showing two illustrative I-V curves corresponding to two measurement conditions for performing the current and voltage measurements used to determine the photodiode performance parameters, in accordance with an embodiment of the present invention;

Problems solved by technology

Additionally, it is sometimes useful to determine the dynamic impedance-area product R.sub.0A and the external quantum efficiency .eta. parameters individually.

There are, however, difficulties in determining these photodiode performance parameters using standard techniques.

First, for high-volume production of photodetectors, the amount of experimental data required to extract R.sub.0A from I-V measurements is prohibitively large and time-consuming to produce.

There are two primary difficulties with this simple two-point analysis.

Because the ideality factor is in the exponential, substantial errors can be made in the estimation of R.sub.0A if n is not known or imprecisely estimated.

Second, the background flux present during the I-V measurement is often not controlled and can vary from measurement to measurement.

The foregoing drawbacks of conventional performance parameter measuring techniques can limit the ability to perform high throughput screening of photodetector performance at low cost.

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