Photodiode structure

[STEVE2]

On a photodiode does anyone know what the N+ region between the cathode and the N substrate is for?

Thanks in advance!

View attachment 38809

 

[STEVE2]

Found the answer ... It's an ohmic contact to reduce the resistance between the semi-conductor and the metal contact.

 

[gogo2520]

Hello Steve
      Were did you find the answer at?
                                                  gogo

 

[STEVE2]

http://www.osioptoelectronics.com/products/02-07_PDiodeChar_OSIOpto_0.pdf

"To form an ohmic contact another impurity diffusion into the backside of the wafer is necessary. The impurity is an N-type for P-type active area and P-type for an N-type active area."