Small Gap between parallel plates

[mcodesmart]

Any ideas on how one can make a small gap (~10-50nm) between two parallel plates and maintain a known distance between them. I have two very flat surfaces and I would like to maintain a small gap (known gap) across them. I searched in the literature but I came up with nothing so if you have any ideas, that would be great.

 

[berkeman]

Any ideas on how one can make a small gap (~10-50nm) between two parallel plates and maintain a known distance between them. I have two very flat surfaces and I would like to maintain a small gap (known gap) across them. I searched in the literature but I came up with nothing so if you have any ideas, that would be great.

What are the dimensions of the plates? What are they made of? Do they have a voltage between them?

 

[mcodesmart]

What are the dimensions of the plates? What are they made of? Do they have a voltage between them?

The dimensions of the plate, (10mmx 10mm) and made from very flat and polished Si wafers. No voltage between them but I understand van dew Waal interactions is an issue at those lengths?

 

[256bits]

Could you put some nano-particles between the plates to keep them seperated.

 

[Bandit127]

Does the gap have to be air?

I was thinking a film of thin oil but it turns out they tend to be microns or 10s of microns thick so no good for this.

 

[etudiant]

Presumably the gap needs to be maintained in the face of potential disturbances, so there is already a need for some distance adjustment mechanism.
Afaik, the steppers for lithography offer positioning to a few nanometers, so presumably one could measure the gap continuously and adjust as needed, probably with a capacitance based gap measuring technique. One issue would be keeping the plates parallel.