I already have surface analysis instrumentation – why do I need a MiniSIMS?
No analysis technique is ideal for all problems, and each (including SIMS) has its strengths and weaknesses. The low cost of the MiniSIMS means that it is realistic to operate it as a routine analysis tool in combination with other techniques, building up the answer from several viewpoints rather than pushing any one technique to its limits. For example, most Millbrook MiniSIMS instruments are located in the same analysis laboratory as an SEM/EDX instrument.

How does SIMS compare with other surface analysis techniques?
SIMS provides a unique combination of elemental and organic information from the surface and near surface molecular layers of a solid. The high sensitivity and excellent signal/noise make SIMS a very fast analysis technique, particularly in imaging mode where an image can be acquired in well under a minute. The comparison with other analytical techniques (EDX, XPS, AES) is covered in detail in the New Tools for the Surface Engineer article downloadable from this website.

What types of samples can be analysed in a MiniSIMS?
The MiniSIMS operates at high vacuum (10-6 mbar) not ultra-high vacuum, so there are few restrictions on materials; obviously any volatile materials will not remain on a surface when it is introduced into the vacuum chamber. Insulating samples can be analysed using an optional charge neutralization system to reduce charging of the surface under the incident primary ion beam. Powder samples can be analysed if appropriately mounted. Thin films of non-volatile liquids can also be easily prepared, which is useful for acquiring reference spectra e.g. of potential contaminants.

What size of sample can be analysed in a MiniSIMS?
The sample loading system on the MiniSIMS instrument can accept samples up to 12.5 mm in diameter and 6.5 mm in thickness. However, the instrument is designed to allow modification of the sample loading chamber, and we are always willing to discuss customised sample handling arrangements to accommodate specific sample types.

How can a room-sized SIMS system be made into a desktop instrument?
It can’t! When we designed the MiniSIMS we did not start with a conventional SIMS system and decide what to leave out – rather we started with a blank sheet of paper, included only the essential items, and had specific objectives for size and cost of the finished instrument. Many components were not available in the size we required, and these were all designed in-house.

Why is the MiniSIMS so easy to operate?
The instrument was designed for ease of operation, and to some extent this has been achieved by removing the flexibility for a skilled operator to optimise analysis conditions for each individual sample. The MiniSIMS therefore gives a “good” result on the majority of samples, and crucially allows this to be achieved by any operator with minimal set-up time.

How does the performance of a MiniSIMS compare with a conventional SIMS system?
Unfortunately this common question does not have a simple answer because not all conventional SIMS instruments are designed for the same purpose. In particular, some instruments are intended for depth profiling of semiconductor wafers (which requires high primary ion currents and a low mass range) whereas others are intended for analysis of polymers and pharmaceuticals (which requires low primary ion currents and a high mass range). The better approach is to try the MiniSIMS on samples that are typical to your organization to see if the instrument will provide the information you require.

Do you have plans to improve the MiniSIMS performance?
The MiniSIMS offers a balanced level of performance that allows static, imaging and dynamic SIMS capability. As with a Hi-Fi system (where upgrading an amplifier without improving the speakers would have little benefit), altering one part of the MiniSIMS configuration would necessitate changes in several other components. However, there is an on-going programme of development, which will eventually extend the product range with different versions of the MiniSIMS.

How many MiniSIMS instruments have been installed?
Millbrook is still a relatively young company, and our user base is corresponding small. There are now over 20 instruments in operation in Europe, North America and Asia, but our user base is now rapidly expanding. We can usually arrange for a reference from an existing user if this would be helpful.

How much does the MiniSIMS cost?
Taking together the low capital cost, low maintenance and consumable costs, low personnel costs, fast sample throughput and high up-time, the MiniSIMS offers a SIMS analysis at approximately 15% the costs of conventional SIMS analysis. Your local distributor will be able to quote an exact price for a given specification instrument.

What options are available for the MiniSIMS instrument?
Charge neutralization (to allow the analysis of insulating samples) and depth profiling capability are both optional extras, but in practice nearly all instruments have been purchased with these options installed. We also offer software for post-acquisition processing and display of spectra, and a library of reference spectra is also available. A video camera is available to provide an optical reference image. There is also some flexibility in the sample loading configuration (see above).

Where can I find out more about SIMS and surface analysis?
See our About SIMS Page, which also contains links to other useful websites.