Problems with the current design of ellipsometers

[Grambo777]

Hi folks!

For those of you who are familiar with ellipsometers, are the following some significant pains/problems with the apparatus? Are there other significant pain points?

1. The machine is too bulky.
2. The change of angle is too slow.
3. The minimum angle is limited by thickness of arms.
4. The arms restrict the access for the imaging system thus limiting resolution.
5. Angular manipulators of heavy arms require precise and expensive mechanical equipment.

Thank you! We are researching various improvements to this apparatus.

 

[berkeman]

Welcome to the PF.

Sounds like a schoolwork assignment. Or is this for your work somehow?

In either case, what are your thoughts? Have you looked into other ways of measuring thin films? What applications do you want to support with your improved design?

http://www.angstec.com/fckimages/image/product/Spectroscopic Ellipsometer SE300BM.jpg

 

[Grambo777]

Welcome to the PF.

Sounds like a schoolwork assignment. Or is this for your work somehow?

In either case, what are your thoughts? Have you looked into other ways of measuring thin films? What applications do you want to support with your improved design?

http://www.angstec.com/fckimages/image/product/Spectroscopic Ellipsometer SE300BM.jpg
View attachment 244106

Thanks for the welcome! :)

We have a new design in mind which will be published in a couple of months. But, before we spend money on building an ugly prototype, we want to see if we properly identified some real problems with current machines. So far, some of our researchers identified the listed issues.

Are you in the elliosometer business?

Cheers!
G

 

[berkeman]

Are you in the elliosometer business?

No, just hoping to help facilitate getting you some good responses.

Will try paging a few folks who may be able to help: @Andy Resnick @Dale

 

[Grambo777]

No, just hoping to help facilitate getting you some good responses.

Will try paging a few folks who may be able to help: @Andy Resnick @Dale

Much appreciated!
If the proof of concept project goes forward, we will be looking for interested mentors as well.
Cheers!
G

 

[berkeman]

Is your product mainly targeted at thin film measurements, or do you have other applications of ellipsometers in mind?

 

[Dale]

No, just hoping to help facilitate getting you some good responses.

Will try paging a few folks who may be able to help: @Andy Resnick @Dale

Sorry, I had never even heard of an elipsometer until today.

 

[Grambo777]

Is your product mainly targeted at thin film measurements, or do you have other applications of ellipsometers in mind?

Is your product mainly targeted at thin film measurements, or do you have other applications of ellipsometers in mind?

Targeted for thin film measurement for now.

 

[Grambo777]

Sorry, I had never even heard of an elipsometer until today.

No worries! Thanks Dale!

 

[Andy Resnick]

Summary: Identifying current problems/pains with ellipsometers.

Hi folks!

For those of you who are familiar with ellipsometers, are the following some significant pains/problems with the apparatus? Are there other significant pain points?

1. The machine is too bulky.
2. The change of angle is too slow.
3. The minimum angle is limited by thickness of arms.
4. The arms restrict the access for the imaging system thus limiting resolution.
5. Angular manipulators of heavy arms require precise and expensive mechanical equipment.

Thank you! We are researching various improvements to this apparatus.

I used an imaging IR ellipsometer a long time ago (Mueller matrix/Stokes vector) and while I have some ideas for improvement, I'm not sure we are talking about the same kind of device.

Certainly, your points are valid- the required precise angular positioning of source and detector is what drives a lot of the size/slowness/complexity. However, I would also expect the device and measurement requirements in UV, visible, or IR lead to significant application-specific design choices.

For example- are you aiming at a spectral measurement, an imaging measurement, or trying to combine both? Do you have a specific performance metric you are trying to optimize? Am I (unwittingly) helping you compete with J.A. Woolam?

 

[Grambo777]

I used an imaging IR ellipsometer a long time ago (Mueller matrix/Stokes vector) and while I have some ideas for improvement, I'm not sure we are talking about the same kind of device.

Certainly, your points are valid- the required precise angular positioning of source and detector is what drives a lot of the size/slowness/complexity. However, I would also expect the device and measurement requirements in UV, visible, or IR lead to significant application-specific design choices.

For example- are you aiming at a spectral measurement, an imaging measurement, or trying to combine both? Do you have a specific performance metric you are trying to optimize? Am I (unwittingly) helping you compete with J.A. Woolam?

Hi Andy, nice to meet you!

As we are a university, we don't compete with J.A. Woolam, Horiba or other such companies. Our design will be available to any interested company.

I will get back to you on expected applications.

Cheers,
Graham

 

[Grambo777]

Hi Andy, nice to meet you!

As we are a university, we don't compete with J.A. Woolam, Horiba or other such companies. Our design will be available to any interested company.

I will get back to you on expected applications.

Cheers,
Graham

I used an imaging IR ellipsometer a long time ago (Mueller matrix/Stokes vector) and while I have some ideas for improvement, I'm not sure we are talking about the same kind of device.

Certainly, your points are valid- the required precise angular positioning of source and detector is what drives a lot of the size/slowness/complexity. However, I would also expect the device and measurement requirements in UV, visible, or IR lead to significant application-specific design choices.

For example- are you aiming at a spectral measurement, an imaging measurement, or trying to combine both? Do you have a specific performance metric you are trying to optimize? Am I (unwittingly) helping you compete with J.A. Woolam?

Talked with the researchers today, and the elements they use in their design should be valid for the wavelength ranges you mention. The aim is to perform spectroscopic ellipsometry (with a broad-range light source in the illumination arm and a spectrum analyzer at the detection side). We are interested in both variable angle ellipsometry with high-resolution microscopy.

Cheers!