P-N Junction Depth: Affect on Semiconductor Device Performance

[mmaarrkk]

Hi,

Could anyone explain how the affect that P-N junction depth has on the performance of a semiconductor device? Are there any devices which would benefit from having a much larger junction depth?

 

[M Quack]

For example, it affects the capacitance of the device, which can be important in high-frequency applications.

Also, for x-ray detector photo diodes P-I-N diodes are used to increase the depth of the depletion layer in order to increase the active volume. Silicon is rather light and x-rays can penetrate quite deep through silicon. So most photons would simply pass through a thin, normal depletion layer without being absorbed, and thus without creating an electric signal in the detector.

http://www.hamamatsu.com/eu/en/product/category/3100/4001/4103/S3204-08/index.html