# Ohmic contacts

by Excom
Tags: contacts, ohmic
 P: 45 Hallo Is there someone that can explain why Al can be used to form Ohmic contats to both p- and n-type Si? When looking at a Ohmic junction between a metal and a semiconductor, it is formed when the work functions are as follows: $$\Phi_m$$>$$\Phi_p$$ and $$\Phi_m$$<$$\Phi_n$$. How can Al fulfil both or is there something that I am not aware of?