Why are aluminium contacts in schottky diodes connected to doped portion of silicon?

[gilbertomaldito]

WHy is it that the aluminum contacts on schottky diodes are connected to the lightly doped portion of the silicon? Unlike on ordinary diodes that they are connected on the heavily doped silicon?

 

[FvM]

Re: schottky diodes???

I guess, it's writte in any serious semiconductor textbook. Metal to heavy doped material is an ohmic contact, metal to n- is a junction.

 

[kamesh kumar]

Re: schottky diodes???

Can anyone help me to understand how Schottky diode works in a Pre-distorter circuit?

 

[kamalifard]

Re: schottky diodes???

schottky diodes produced by junction of ametal and n type semiconductor and have a little revers biastelorant voltage

 

[sujojk]

Re: schottky diodes???

Every junction formed between a metal and a semiconductor will act as a diode. But the work function (forward drop or depletion region) is inversly proportional to the doping concentration of the semiconductor.

If the semiconductor is lightly doped, the width of the depletion region will be considerably wide enough to act as a p-n junction having low forward drop (than ordinary semiconductor-semiconductor junction)

If the semiconductor is highly doped, then the depletion region will be very thin and it will act just as a continuation of the metal, forming an ohmic contact. (A contact is called ohmic when it obeys ohm's law perfectly)

Hence in ordinary diodes where metal-semiconductor junction is made only for making electrical contacts use highly doped semiconductor whereas in schottky diodes, it is necessary that the semiconductor region should be doped lightly.