Scanning Helium Ion Microscope

In summary, the helium ion microscope is going to be way way better than the electron microscope. Does anyone know the significance of this piece of equipment?
  • #1
Leopold Infeld
55
0
How is this microscope going to be way way better than the electron microscope? Does anyone know the significance of this piece of equipment?

Website links would also be nice...

thanks
 
Physics news on Phys.org
  • #2
http://nanotechwire.com/news.asp?nid=2120&ntid=121&pg=1

Helium Ions have a much shorter wavelength than electrons for a given acceleration potential because of their greater mass. The minimum resolvable distance you can get (for any microscope) is roughly half the wavelength, so the shorter wavelength means SHIMs potentially can achieve much higher resolutions than standard SEMs.

I'd venture the SHIM will offer maybe a thousand fold increase in resolution, pushing resolvable distances down to the order of picometers, giving us a glance at the 'picoscopic' world for the first time.

Claude.
 
  • #3
Have there been any advancements in this field? Like papers, developements etc. I heard that this microscope has been in development for 10 years already.. what have they beeen doing during then?

thanks again

LI
 
  • #4
Since the product is being developed by a commercial venture, information about their progress is likely to be scarce. Access to patents is probably the best way to get information on the SHIM, that is, if they have submitted any.

Claude.
 
  • #5
How do I get hold of patents?

thanx
 
  • #7
do u mean to say that except for ALIS, no one has ever thought about this idea before??
 
  • #8
Potentially people have, however ALIS seem to have been the first to forsee the current roadblocks present in improving SEMs, and thus got a head start in front of everyone else in developing the SHIM (i.e. they were able to 'sell' the idea of a SHIM first). Getting the idea is one thing - getting people to part with their cash to fund your idea is another entirely!

The reason other groups don't jump on the bandwagon is twofold. ALIS has a head-start, which means they won't be able to capitalise on the advantages (i.e. a monopoly) that come with developing something this early in the technological life-cycle. Secondly, the technology isn't proven yet, the ALIS (well, its backers anyway) is taking a gamble in spending all this money developing this product when there is no guarantee that a) It will work and b) There will be demand for it if they do develop it, at the price they can make it for.

Once the technology has been proven to both a) work and b) make money, you will see other companies start to develop their own SHIMs.

Claude.
 
  • #9
Ok, thanks claude, I have to submit this report in two weeks time and information is as scarce as desert water since its such a new technology. All the information that I have are no way near my comprehension since there are still no layman articles yet.
 
  • #10
There is plenty of information on Scanning Electron Microscopes though, a Scanning Helium Ion Micorscope will still operate on the same fundamental principle - using charged particles with extremely short wavelengths (compared to optical wavelengths) to achieve super-high resolution. A lot of information available of SEMs will still apply to SHIMs as well in a broad sense.

For your report...

You should mention the diffraction limit, and what diffraction limited resolution means. This will allow you to make a solid connection between the wavelength of the particle and resolution - a connection you will need when explaining the advantages (i.e. improved resolution) of using helium ions as charged particles rather than electron.

You should also mention some of the technical challenges facing SHIMs - namely finding sources and detectors for helium ions. Also, the heavier mass of the helium ion means they are harder to 'steer' into the right position than electrons - meaning you need stronger magnetic fields to control everything.

The highly technical details of the SHIM are unlikely to make good reading, so I wouldn't bother mentioning them. For a report for a non-specialised audience, you just want to give them the 'gist'. Keep in mind that the most fascinating thing people will likely find about the SHIM is the fact that when it is developed, people will start breaking records in terms of being to resolve tiny objects, the next step in the microscopic -> nanoscopic -> picoscopic progression.

I hope that little rant provides some direction for your report. Good luck.

Claude.
 
  • #11
i guess the main problem with a scanning helium ion microscope would be the extra mass of the ion compared to the election. It might end up causing damage to the sample.
 
  • #12
Wow, Claude, I am going to reference u in my report, thanks so much. I juz realized that diffraction limit thing.

I actually am going to do two microscopes in one paper now. The other is on STORM, some new technique developed at Harvard by Xiaowei Zhuang et. al.

And sdemjanenko, there will be negligible sample damage as helium ions produce no appreciable sputtering. Even for life science applications, helium ions are light enuff so that they don't damage the delicate sample. But other ions like Gallium FIBs could damage the sample.
 
  • #13
Some info about the SHIM.
The SHIM uses a single atom for it's emission source.
A single helium ion generates many secondary electrons so very low beam currents can be used without loosing signal to noise.
The surface interaction is very different from a conventional SEM, even at high beam energies the SHIM gives good surface information while the SEM must go to low beam energies and suffer a resolution loss.
Rutherford backscatter imaging has excellent material contrast and is not sensitive to sample charging effects.
The SHIM images low Z materials better than a SEM, carbon nanotubes look amazing and have high contrast compared to a SEM.
These microscopes should be available sometime in 2007.
 
  • #14
Claude Bile said:
I'd venture the SHIM will offer maybe a thousand fold increase in resolution, pushing resolvable distances down to the order of picometers, giving us a glance at the 'picoscopic' world for the first time..

that's impossible. how will you resolve something several orders of magnitude smaller than the probe? at best they're reporting about a quarter of an angstrom.
 
  • #15
Wait, what?

First of all, why ressurect a year-old thread?

Second, you do know that 0.25 A = 25 pm right? In which case we agree (sort of)?

Claude.
 
  • #16
Claude Bile said:
Wait, what?

First of all, why ressurect a year-old thread?

Second, you do know that 0.25 A = 25 pm right? In which case we agree (sort of)?

Claude.

I just ran across this thread, interesting stuff. Sorry to "resurrect" it yet again, just interested in the discussion and its new to me.

Seems like the best resolution those ALIS guys are getting is .24 nm, not .25 angstroms as quoted above. So really its not yet pure pico world since that is 240 pm but you can say its bordering into that world. Now the wavelength of helium atoms is a lot smaller than electrons for a given energy so theoretically yes there should be some amazing resolution improvement, but I think it comes down to what kind of spot size they are able to focus it down to, and that is probably the issue.

By way of contrast, the best TEM resolution in the world seems to be from FEI Titan microscopes, their data sheets say that they have a resolution of 80 pm, so a lot better than 240 pm, considering x and y that means pretty much 9 times more information/pixels. However that is transmitting the electrons *through* a thin specimen and then analyzing the diffraction pattern to get that, not relying on a focused spot rastered across a specimen and collecting backscattered electron flux.

So, in theory an ALIS would have probably much better resolution than that by a factor of something like 80 if you could somehow run it in TEM mode (guess you would call that a TAM, transmission atom microscope), but then you probably could have done that a long time ago if it were possible or made sense. I'm guessing somehow atoms knocking into other atoms poses some problems in elastic vs inelastic collisions that you don't have with electrons (the challenge with ALIS was to get the He ion source stable so you could form a small beam, not to emit a bunch of He ions through a specimen in a larger area).

Anyway, regardless of this the ALIS is amazing, and that they figured out a way to make the He stable enough is pretty mind boggling, hats off to those smart kids out in frigid MA! Its a relatively new technology and they probably have room to tweak things down further to even smaller resolutions.

The above is just my guess, I don't know enough to speak to the subject fully, would be great if some microscopy expert would jump in here and tell us why exactly the resolution is not knocking the socks off TEM resolutions...
 
Last edited:

What is a Scanning Helium Ion Microscope?

A Scanning Helium Ion Microscope (SHIM) is an advanced imaging tool used in scientific research to produce high-resolution images of nanoscale objects. It works by focusing a beam of helium ions onto a sample, and detecting the secondary electrons that are emitted. This allows for incredibly detailed imaging of surfaces, even those that are typically difficult to image using traditional microscopy techniques.

How is a Scanning Helium Ion Microscope different from other microscopes?

Unlike traditional microscopes that use electrons or photons, a Scanning Helium Ion Microscope uses helium ions as its primary imaging beam. This allows for higher resolution images and the ability to image non-conductive samples, which are typically difficult to image using other microscopy techniques.

What are the main applications of a Scanning Helium Ion Microscope?

Scanning Helium Ion Microscopes have a wide range of applications in various scientific fields, including materials science, nanotechnology, biology, and geology. They are used to study the surface topography, composition, and electrical properties of a variety of materials at the nanoscale level.

What are the advantages of using a Scanning Helium Ion Microscope?

One of the main advantages of using a Scanning Helium Ion Microscope is its ability to produce high-resolution images of non-conductive samples. It also has a longer depth of focus compared to other microscopy techniques, allowing for more precise imaging of 3D structures. Additionally, SHIMs can operate at lower voltages, reducing the risk of sample damage and prolonging the lifespan of the instrument.

What are the limitations of a Scanning Helium Ion Microscope?

One limitation of a Scanning Helium Ion Microscope is its high cost, making it less accessible to smaller research facilities. Additionally, the imaging process can be time-consuming, and the instrument requires a high level of technical expertise to operate and maintain. Also, the helium ion beam can cause surface damage to delicate samples, so careful consideration must be taken when choosing samples for imaging.

Similar threads

  • General Discussion
Replies
1
Views
340
Replies
13
Views
2K
Replies
16
Views
3K
Replies
4
Views
785
  • Special and General Relativity
Replies
10
Views
364
  • Materials and Chemical Engineering
Replies
3
Views
1K
Replies
5
Views
2K
Replies
1
Views
1K
  • Chemistry
Replies
4
Views
689
Replies
3
Views
1K
Back
Top