An optical measurement method for PN junction depth

The light spectrum response of a pn junction structure was analyzed using a one-dimensional photodiode simulator. With the numerical modeling of a one-dimensional photodiode structure, a monotonic relationship of wavelength at the light spectrum peak response versus pn junction depth is derived. An optical measurement method for pn junction depth is presented. From the comparison of simulated and measured light wavelength of the peak optical response, the pn junction depth can be uniquely determined, achieving a reasonable accuracy for different depths of the junction. Some experimental results are given to support the validity of the optical measurement method.<
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