[mems-talk] GaAs Au-Ge ohmic contact

[Brent Garber]

Sochin,

Thickness matters.  I buy Au with 12% Ge already in it.  For my use, I evap 650A
AuGe, then 150A of Ni, then top it off with 1700A of Au.  Then I sinter it a
425c for 20 seconds.

Brent

sachin narwade wrote:

> Dear all,
>           i am having a problem getting a good ohmic contact on n-GaAs. As
> suggested in theory, i have used Au-Ge( 88%:12%) and evaporated them
> together in a Tungsten boat in a vacuum coating unit. but i am still getting
> schottky diode like characteristics of the contact. i have also annealed the
> sample after metallization at temperatures like 360-400 degrees C (not RTA)
> for 1-2 mins but still am not getting good ohmic contact. is there any
> specific thing i should follow while evaporation? kindly suggest me any
> solutions.