What are the size limitations of the mentioned measurements?
Can I perform these measurements on a pixel, let's say few microns to few dozen microns square?
Are there any limitations on the thickness?
Is there a major difference between 4PointProbe and Van Der Pauw measurements?
What is a reasonable magnetic field strength needed for Hall-Effect measurements and should it be relative to the probes lengths?
Thanks
Usually the Hall effect can be detected very good on a 1 cm x 5 mm semiconductor sample with a 0.1 T to 0.3 T magnetic field with 10 Volts and 1 mA driving voltage and current. The semiconductor sample has gold deposited on the surface of the semiconductor to make the contacts and silver paste is used to solder the wires to the gold contact.
On lower size semiconductor samples you need very high magnetic field. In an integrated circuit (28 V, 50 mA that can detect 1 mT) the dimension of the Hall detector is 0.5 mm x 0.5 mm, but the IC has an amplifier for the Hall voltage.
Oh, I thought that at smaller sizes it will get easier to detect the Hall voltage. Both because its easier to achieve homogeneous magnetic field and the resistance is lower, therefor the current is higher.
Thank you Valentin for the information.
Rh= 1/ne
n = 10^17 cm^-3
Vh = Ix Bz / Rh*w
w = 10^-6 (thin film)
Ix = 1 mA
Bz = 0.2 T
Vh = 1 mV to 1 V
The size of the contacts is 1 mm^2 , under 1 mm^2 is very difficult to make the contact
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