In AlGaN/GaN HEMT and MgZnO/ZnO HFET, 2deg form. All fabrication results show that 2DEG is measured by hall method and C-V depth profiling. I am bothered about the procedure of the C-V depth profile?
How does thickness change during the measure of a C-V profile?
I attached reference paper for more information.
Your question makes sense. The answer involves 2 points: the capacitance of a 2D device, and what is measured in a std C-V experiment.
Consider first a pure 2D situation, i.e. a 2D electron or hole gas in a quantum well located on the top of a semi-insulating or insulating substrate, with a contact to the 2D gas made using a side electrode located in the frontside (e.g. the drain or source of a HEMT, or a circular electrode surrounding the gate).
In this case, the C-V experiment measures the top gate/2DEG capacitance in series with the resistance of the 2DEG from below the gate to the side electrode.
If the 2D electron gas is not to much depleted, or if a backside conducting layer can ensure a low enough series resistance (such as the ZnO layer in the paper you attached) so that the condition 2pi.f.R_series.C_cap
Of course, the forelast paragraph of course of my preceding answer, should be read as:
In a 2DEG device, the C^(-2)(V) processing used in a standard way for 3D depletion zones doesn't make sense.
2DEG profiling in HEMT using C-V:
For HEMT (depletion type, Threshold voltage (Vth)
I am satisfied with both the explanations. My questions deals with the amount of metal we use to make contact with 2DEG...Is the use of such enormous amount of conducting material in the structure not a matter of thought?
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Semiconductor