I have a circular PZT layer deposited by PLD method. The dimensions are: 20um diameter and 350nm thick. It has 100nm Pt electrodes sputtered on the top and bottom. I would like to know what is the maximum voltage it can withstand?
I would assume that the withstanding voltage will increase proportionally with the thickness. Is it correct?
Typically the breakdown field of PZT films is around 1MV/cm, so for a thickness of 350 nm, the maximum voltage is around 35V.
But as a precaution, if the films are not of very good quality maybe the voltage should be limited to about 20V.
Gilles Poullain Thanks for your answer.
Is there any literature where I can find the breakdown field of PZT films (the value you mentioned)? Also, is it safe to assume that the breakdown field varies with thickness yet not dependent on the surface area (diameter) of the PZT patch? Let me know.
Here is an article by L. Cross et al (JAP 77 3891(1995)) where Figure 8 answers your questions. See attached file.
In principle the surface area should not influence the breakdown voltage, but my experience leads me to say that in practice this can happen for small surfaces (typically less than 100 nm²).
You can find more answers to your questions in the literature of the 1990s in journals such as ferroelectrics or integrated ferroelectrics.
Besides the area, tha corners of the electrode will need some consodtation!
Also the limits of thw Vbd will be defined on the level of dessects.
The biger grain boundaries are the weaker spots.
So surface is a key for investigation also.
Remark that the breakdown voltage of any vacuum deposited thin film will strongly depend on the quality of such thin film (pin holes, density etc.). A safety margin of 100% is a good approach in case you didn't do a detailed evaluation of coating quality !
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