Ohmic contacts


by Excom
Tags: contacts, ohmic
Excom
Excom is offline
#1
Mar16-09, 04:29 AM
P: 44
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: [tex]\Phi_m[/tex]>[tex]\Phi_p[/tex] and [tex]\Phi_m[/tex]<[tex]\Phi_n[/tex]. How can Al fulfil both or is there something that I am not aware of?
Phys.Org News Partner Physics news on Phys.org
Researchers develop scalable methods for manufacturing metamaterials
Researchers find tin selenide shows promise for efficiently converting waste heat into electrical energy
After 13 years, progress in pitch-drop experiment (w/ video)
Naty1
Naty1 is offline
#2
Mar20-09, 03:14 PM
P: 5,634
Does this help:
Aluminum is another important contact metal for silicon which can be used with either the n-type or p-type semiconductor. As with other reactive metals, Al contributes to contact formation by consuming the oxygen in the native oxide. Silicides have largely replaced Al in part because the more refractory materials are less prone to diffuse into unintended areas especially during subsequent high-temperature processing.
Wikipedia: http://en.wikipedia.org/wiki/Ohmic_c...ds_of_contacts
Excom
Excom is offline
#3
Mar26-09, 04:38 AM
P: 44
No it does not help.

I do understand that Al can react with oxygen to form Al2O3 and thereby consum the native oxide. However, this do not explain why Al can make ohmic contact to n- and p-type silicon.


Register to reply

Related Discussions
Ohmic Or NoN ohmic Introductory Physics Homework 3
Non ohmic device Introductory Physics Homework 1
Ohmic loss, ohm's law, resistance etc...... Classical Physics 5
help listing non ohmic devices Electrical Engineering 2
Is a filament lamp an ohmic device? Engineering, Comp Sci, & Technology Homework 2