I have executed the c-v measurement of Al/HfO2/Al structure using impedance analyzer and I have found a non linear relationship between c & v. As i see, the case of above said structure resembles to a parallel plate capacitor. So, as I know capacitance with voltage in case of parallel plate capacitor remains constant. please help me out.
Dear Artur sir, I have performed measurement in air by using silver paste to make contact for interfacing of my structure with impedance analyzer. I used -1 to 1 V range without facing any breakdown.
At what frequency did you measure the capacitance?
Secondly, I am wondering what is the thickness of the oxide? If there is any tunneling, then you will definitely get some non-uniformity in C-V.
Dear Ravi sir, your attached reference is related to MOS capacitor but my fabricated structure is Metal-Insulator-Metal type i.e. parallel plate capacitor. So I would like to know the reason for change in capacitance for this structure. My measurement frequency is of the order of MHz and dc sweep voltage is -3 to3 volt.
Thank you Ravi sir, now I have got your point. So, can you tell me some references to find the depth of these mechanism (leakage and frequency). Further, is it possible to relate these variations with some material related properties, like dielectric properties.
It would great to see the plot. All caps parasitic R and L which might look non-linear. My apologies if you already checked this.
Dear Satyendra,
welcome,
I know that i cam very late to your question. As i see there in no satisfactory answer to you question, i will try to give an answer to it. It is so that HfO2 shows ferroelectric properties making the C-V behavior of this material nonlinear. So, the nonlinearity is because of the ferroelectric behavior of such material.
In order to prove that you need to measure P-V diagram of this capacitor. It will show hysteresis.
For more information about this material please see the link: http://www.namlab.de/research/dielectric-materials-1/hafnium-oxide-ferroelectrics
Best wishes
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