Behind the scenes of our MEMS production at EKL

Behind the scenes of our MEMS production at EKL

See how we produce consistent high quality MEMS devices for our customers.

Process Engineer from EKL explaining the latest improvements to DENSsolutions quality control employees.

DENSsolutions and EKL (Else Kooi Laboratory) have been working together since the founding of our company in 2012. All our MEMS devices, from Wildfire chips to more intricate Stream Nano-Cells are developed in conjunction with this laboratory and produced here in Delft, the Netherlands. Being partly an academic laboratory, EKL is the perfect partner for us to develop innovative new ways to expose your sample to a variety of stimuli.

Bottom chips of our Stream Nano-Cell MEMS devices.

Rocket science

Chip production might not be as explosive as rocket science, but it is just as challenging. We produce numerous chips, and every single one is of consistent high quality which is especially challenging when you’re working on the sub micrometer scale. To ensure top production over so many chips, we need sophisticated processes. Luckily for us, we can count on a dedicated and enthusiastic team of experts at EKL that always strive to meet our demands.

EKL employee showing the photomask for one of the layers required for the manufacturing of the Wildfire chips.

Overcoming challenges

So what does it actually take to produce these nanodevices? Since they are at the heart of our solutions, we take a lot of care in their manufacture.

We endeavour to make our MEMS devices precise and with tight tolerances, free of contamination, reproducible and affordable. It is precisely these values that drive our production process. Each step is carefully inspected for cleanliness, consistency and quality.

 What is a MEMS device?

MEMS stands for Micro-Electro-Mechanical Systems. All our ‘sample carriers’ are MEMS devices. We normally don’t use the description ‘sample carriers’ because they do way more than just carrying the sample. They expose the specimen to a wide variety of stimuli and provide quantitative measurements. We talk about “Nano-Chips” for Wildfire and Lightning, but when we stack chips to form closed channels for gas or liquid we refer to them as “Nano-Reactors”, for Climate, and “Nano-Cells”, for Stream and Ocean.

Historically, the earliest microfabrication processes were used for integrated circuit production, but in the last decades extended and re-adapted microfabrication methods have led to new processes for MEMS development.

A small piece of dust on a smartphone chip is usually unnoticeable. However, even the smallest amount of dust on our MEMS device can obstruct the nanoscale view of a sample. Our MEMS must be extremely clean and this is inspected between the many stages of its production. Overall, the development of these types of devices brings challenges in many areas of science and engineering: chemistry, physics, materials science, fabrication processes, but it is also giving rise to many kinds of interdisciplinary research.

Ellipsometry is an optical technique used to investigate the dielectric properties of thin films.

Photolithography step to expose the photomask within the wafer.

Nanometer precision

Next to cleanliness we also place high demands on our chips in terms of specific features that are required to do research with a high level of reliability. Our Stream Nano-Cells, for instance, need to be able to guarantee the right liquid thickness irrespective of the tolerances of the o-ring that seals them. Similarly, the windows need to ensure a reliable control of the bulging and a constant viewing area. We use different etching and deposition steps to create the spacers inside your Nano-Cell that are responsible for channeling the liquid. Similarly, during the window formation, we have to etch away exactly the right amount of material underneath, while keeping the layer intact with a precision of nanometers.

For some mainstream applications, over-etching of a few nanometers might not be important. In our case, keeping a specific thickness out of spec might result in the need to throw away the whole wafer and start all over again. If we have already accomplished 70-80% of the process, you can imagine how precious this can be. So we have to constantly push the machines to their limits to make sure we just etch exactly the right amount, over and over again.

 Did you know?

There are up to 25-30 machines involved in the production of our MEMS devices. Each of these machines has a set of unique variables that need to be just right. Think of pressure, power, chemistry of gases, temperature, frequency and time as some of the variables that have to be adjusted for the different machines in order to create the right recipe. Only by setting these in the right way, would the operator get the necessary chemical affinity and deposition/etching rates to successfully manufacture the chip that heats up your sample with super low drift.

Process Engineer at EKL while adjusting the process recipe for one of the most crucial steps within the microfabrication.

Our MEMS are used in research as consumables. You might need to do many experiments using multiple chips to get the result that you want. So our MEMS have to be affordable to fit research budgets.

Each step of our workflow has been enhanced over the years to be as efficient as possible. This decreases lab time and cost, and ensures that each chip in a series has exactly the same specs. Your accuracy is our priority.

“We’re convinced that the MEMS devices are the core competence of our company. It is highly possible that high-impact advances will occur at the intersection of new process technologies and new architectures. Therefore, it’ll be our continuous job to push the limits in a well-planned, structured and innovative way”

Chief Technology Officer Dr. Hugo Perez Garza – DENSsolutions

See how we produce consistent high quality MEMS devices for our customers.

Process Engineer from EKL explaining the latest improvements to DENSsolutions quality control employees.

DENSsolutions and EKL (Else Kooi Laboratory) have been working together since the founding of our company in 2012. All our MEMS devices, from Wildfire chips to more intricate Stream Nano-Cells are developed in conjunction with this laboratory and produced here in Delft, the Netherlands. Being partly an academic laboratory, EKL is the perfect partner for us to develop innovative new ways to expose your sample to a variety of stimuli.

Bottom chips of our Stream Nano-Cell MEMS devices.

Rocket science

Chip production might not be as explosive as rocket science, but it is just as challenging. We produce numerous chips, and every single one is of consistent high quality which is especially challenging when you’re working on the sub micrometer scale. To ensure top production over so many chips, we need sophisticated processes. Luckily for us, we can count on a dedicated and enthusiastic team of experts at EKL that always strive to meet our demands.

EKL employee showing the photomask for one of the layers required for the manufacturing of the Wildfire chips.

Overcoming challenges

So what does it actually take to produce these nanodevices? Since they are at the heart of our solutions, we take a lot of care in their manufacture.

We endeavour to make our MEMS devices precise and with tight tolerances, free of contamination, reproducible and affordable. It is precisely these values that drive our production process. Each step is carefully inspected for cleanliness, consistency and quality.

 What is a MEMS device?

MEMS stands for Micro-Electro-Mechanical Systems. All our ‘sample carriers’ are MEMS devices. We normally don’t use the description ‘sample carriers’ because they do way more than just carrying the sample. They expose the specimen to a wide variety of stimuli and provide quantitative measurements. We talk about “Nano-Chips” for Wildfire and Lightning, but when we stack chips to form closed channels for gas or liquid we refer to them as “Nano-Reactors”, for Climate, and “Nano-Cells”, for Stream and Ocean.

Historically, the earliest microfabrication processes were used for integrated circuit production, but in the last decades extended and re-adapted microfabrication methods have led to new processes for MEMS development.

A small piece of dust on a smartphone chip is usually unnoticeable. However, even the smallest amount of dust on our MEMS device can obstruct the nanoscale view of a sample. Our MEMS must be extremely clean and this is inspected between the many stages of its production. Overall, the development of these types of devices brings challenges in many areas of science and engineering: chemistry, physics, materials science, fabrication processes, but it is also giving rise to many kinds of interdisciplinary research.

Ellipsometry is an optical technique used to investigate the dielectric properties of thin films.

Photolithography step to expose the photomask within the wafer.

Nanometer precision

Next to cleanliness we also place high demands on our chips in terms of specific features that are required to do research with a high level of reliability. Our Stream Nano-Cells, for instance, need to be able to guarantee the right liquid thickness irrespective of the tolerances of the o-ring that seals them. Similarly, the windows need to ensure a reliable control of the bulging and a constant viewing area. We use different etching and deposition steps to create the spacers inside your Nano-Cell that are responsible for channeling the liquid. Similarly, during the window formation, we have to etch away exactly the right amount of material underneath, while keeping the layer intact with a precision of nanometers.

For some mainstream applications, over-etching of a few nanometers might not be important. In our case, keeping a specific thickness out of spec might result in the need to throw away the whole wafer and start all over again. If we have already accomplished 70-80% of the process, you can imagine how precious this can be. So we have to constantly push the machines to their limits to make sure we just etch exactly the right amount, over and over again.

 Did you know?

There are up to 25-30 machines involved in the production of our MEMS devices. Each of these machines has a set of unique variables that need to be just right. Think of pressure, power, chemistry of gases, temperature, frequency and time as some of the variables that have to be adjusted for the different machines in order to create the right recipe. Only by setting these in the right way, would the operator get the necessary chemical affinity and deposition/etching rates to successfully manufacture the chip that heats up your sample with super low drift.

Process Engineer at EKL while adjusting the process recipe for one of the most crucial steps within the microfabrication.

Our MEMS are used in research as consumables. You might need to do many experiments using multiple chips to get the result that you want. So our MEMS have to be affordable to fit research budgets.

Each step of our workflow has been enhanced over the years to be as efficient as possible. This decreases lab time and cost, and ensures that each chip in a series has exactly the same specs. Your accuracy is our priority.

“We’re convinced that the MEMS devices are the core competence of our company. It is highly possible that high-impact advances will occur at the intersection of new process technologies and new architectures. Therefore, it’ll be our continuous job to push the limits in a well-planned, structured and innovative way”

Chief Technology Officer Dr. Hugo Perez Garza – DENSsolutions

Gas Analyzer supporting ex situ Catalyst experiments

Gas Analyzer supporting ex situ Catalyst experiments

Technical Research Engineer Marien Bremmer MSc with the gas analyzer (blue) in the background
Our solutions not only allow for highly controllable in situ experiments, they also allow for ex situ experiments that might save you valuable in situ time. With this ex situ experiment, we were able to prove the performance of the catalyst before moving in to the TEM.

The experiment

We used palladium nanoparticles for our catalyst These particles were dropcasted inside a Climate MEMS based Nano-Reactor. For the gas supply we used the Climate G+ system which allows for up to 3 gases to be mixed. We loaded the system with oxygen and methane as reactive gases and measured carbon monoxide and carbon dioxide as reaction products.

Figure 1. Sample temperature (top) and gas partial pressure (middle & bottom) measured as a function of time.

Catalyst performance

First we used the gas analyzer combined with our accurate temperature control to measure the catalyst performance. The supply of reactants was kept at a constant level (figure 1 – middle graph) while we used our Impulse software to automatically ramp up the temperature of the Nano-Reactor from 300 to 700 °C in 60 seconds (figure 1 – top graph). As a result we measured the level of reactant gases dropping and the level of reaction products rising (figure 1 – bottom graph). We see the levels stabilizing when the temperature is constant.

 

High activity phase shifting

Figure 2. Gas mixture composition into the Nano-Reactor (top), partial pressures of gases flowing out of the Nano-Reactor (middle) and dissipated power by the Nano-Reactor heater (bottom) as a function of time.
During the next experiment, we kept the palladium sample at a constant temperature while increasing the concentration of methane (CH4) from 5% to 10% (figure 2 – top graph). At around  t = 300 seconds you can clearly see fluctuations in the level of reaction products (figure 2 – middle graph). Here we observe the catalyst shifting in and out of a high activity phase that is reached at elevated temperatures. When passing a certain temperature range, this high activity phase can be demonstrated by oscillations in the partial pressure of the gas reaction products. Also oscillations in the power dissipated by the heater (figure 2 – bottom graph) indicates a change of activity at the sample.

At t = 500 seconds we use our Impulse software to drop the level of methane in steps of 0,5%. Measuring the COlevel with our gas analyzer we can clearly see the influence of the first drop in concentration. The COproduction rate starts to more unstable. By dropping the concentration with another 0,5%, the frequency of the fluctuations increases and, after the third drop of concentration, the catalyst starts to shift back to its normal activity phase, stabilizing the COproduction after the fourth drop.

 

High time resolution

Figure 3. Detailed results for partial pressure (top) and power dissipation (bottom) measurements.

We zoomed in at areas A and B and plotted the results from the gas analyzer as well as those from the power dissipated by our 4-point probe temperature control system (see figure 3). This allows us to correlate the two measurements. We see that the reaction gases are in counter phase of each other and that their extremes are in line with the tops of the measured power. This shows not only a very high stability in temperature control but also a very high time resolution.

Conclusions

Thanks to our high accuracy gas analyzer and heating control and measurement, you are able to do ex situ experiments that can give you valuable data. This data can lead to new discoveries or can be used to prepare your in situ experiment better.

Marien Bremmer who conducted the experiment commented:

“Using the Climate G+ in combination with the Gas Analyzer allows you to characterize your catalyst sample ex situ, finding the best gas and temperature conditions for your reaction, and with this data to go to the TEM to finalize your research with real in situ images and spectroscopy.”

Download the
Gas Analyzer Application Note

Technical Research Engineer Marien Bremmer MSc with the gas analyzer (blue) in the background
Our solutions not only allow for highly controllable in situ experiments, they also allow for ex situ experiments that might save you valuable in situ time. With this ex situ experiment, we were able to prove the performance of the catalyst before moving in to the TEM.

The experiment

We used palladium nanoparticles for our catalyst These particles were dropcasted inside a Climate MEMS based Nano-Reactor. For the gas supply we used the Climate G+ system which allows for up to 3 gases to be mixed. We loaded the system with oxygen and methane as reactive gases and measured carbon monoxide and carbon dioxide as reaction products.

Figure 1. Sample temperature (top) and gas partial pressure (middle & bottom) measured as a function of time.

Catalyst performance

First we used the gas analyzer combined with our accurate temperature control to measure the catalyst performance. The supply of reactants was kept at a constant level (figure 1 – middle graph) while we used our Impulse software to automatically ramp up the temperature of the Nano-Reactor from 300 to 700 °C in 60 seconds (figure 1 – top graph). As a result we measured the level of reactant gases dropping and the level of reaction products rising (figure 1 – bottom graph). We see the levels stabilizing when the temperature is constant.

 

High activity phase shifting

Figure 2. Gas mixture composition into the Nano-Reactor (top), partial pressures of gases flowing out of the Nano-Reactor (middle) and dissipated power by the Nano-Reactor heater (bottom) as a function of time.
During the next experiment, we kept the palladium sample at a constant temperature while increasing the concentration of methane (CH4) from 5% to 10% (figure 2 – top graph). At around  t = 300 seconds you can clearly see fluctuations in the level of reaction products (figure 2 – middle graph). Here we observe the catalyst shifting in and out of a high activity phase that is reached at elevated temperatures. When passing a certain temperature range, this high activity phase can be demonstrated by oscillations in the partial pressure of the gas reaction products. Also oscillations in the power dissipated by the heater (figure 2 – bottom graph) indicates a change of activity at the sample.

At t = 500 seconds we use our Impulse software to drop the level of methane in steps of 0,5%. Measuring the COlevel with our gas analyzer we can clearly see the influence of the first drop in concentration. The COproduction rate starts to more unstable. By dropping the concentration with another 0,5%, the frequency of the fluctuations increases and, after the third drop of concentration, the catalyst starts to shift back to its normal activity phase, stabilizing the COproduction after the fourth drop.

 

High time resolution

Figure 3. Detailed results for partial pressure (top) and power dissipation (bottom) measurements.

We zoomed in at areas A and B and plotted the results from the gas analyzer as well as those from the power dissipated by our 4-point probe temperature control system (see figure 3). This allows us to correlate the two measurements. We see that the reaction gases are in counter phase of each other and that their extremes are in line with the tops of the measured power. This shows not only a very high stability in temperature control but also a very high time resolution.

Conclusions

Thanks to our high accuracy gas analyzer and heating control and measurement, you are able to do ex situ experiments that can give you valuable data. This data can lead to new discoveries or can be used to prepare your in situ experiment better.

Marien Bremmer who conducted the experiment commented:

“Using the Climate G+ in combination with the Gas Analyzer allows you to characterize your catalyst sample ex situ, finding the best gas and temperature conditions for your reaction, and with this data to go to the TEM to finalize your research with real in situ images and spectroscopy.”

Download the
Gas Analyzer Application Note

1st European Climate User Meeting

1st European Climate User Meeting

Where we find out how our solutions accelerate research and how we can adapt to new challenges.

DENSsolutions team members together with customers from FHI Berlin, DTU Nanolab Kgs. Lyngby, ER-C Jülich, EMAT Antwerp, ETH Zürich, Johnson-Matthey Didcot, University of Limerick, Trinity College Dublin and Queen’s University Belfast.

A little over 3 years ago, the first Climate in situ gas & heating systems were installed by DENSsolutions at customer sites. Therefore, the time has come to evaluate the results obtained so far by all our European customers and to share experiences. A 2-day meeting was held in Delft, the Netherlands on 5th & 6th June 2019 to provide an open forum for both users and the DENSsolutions team to share their results and suggestions.

Dr. Michele Conroy and Dr. Jennifer Cookman from the University of Limerick sharing their future plans for Climate experiments.

Presentations and discussions

Each Climate user gave a presentation on: their in situ gas & heating research, other research using the Climate system in their departments, and plans for future research.The topics covered included catalyst research on nano-particles, carbon nano-tube growth, and materials science on lamella-type samples. Our team members also gave presentations on our latest product development and newest applications.

Dr. Armand Beche (center) from EMAT Antwerp

Dr. Xing Huang (right) from ETH Zurich

We value the experience and feedback that our users from different institutes and companies, as well as DENSsolutions team members, brought to the discussions. Our discussions were dynamic and covered not only in situ TEM but also experiments that used the Climate Nano-Reactor in other environments such as a Beamline or an X-ray microscope.

Dr. Manfred Schuster from Johnson Matthey sharing insights from their customized beamline experiment

During the conference, new ideas, theories and product feedback were shared so we left with a list of possible improvements for our solutions as needed by the people who use them. These included: ease-of-use items, improvements on MEMS chips, tools to improve sample drop casting, and ideas on how to improve gas & heating control.

Dr. Thomas Hansen DTU explaining on the importance of low dose imaging.

Continuing the conversation

All the participants agreed that we should continue these discussions to improve both in situ TEM research and the tools that facilitate it. DENSsolutions will enable these conversations as part of an online environment as well as by organizing new Climate user meetings. Furthermore we see possibilities to organize forums like this in the future for other products and for users from other regions.

Ronald Marx MSc, DENSsolutions

Our Climate Product Manager Ronald Marx commented at the end of the 2-day meeting:

“It was a great pleasure for me to host all these Climate users in Delft and engage in discussions that reveal both the current and the potential new benefits of doing in situ research with the system’.

Download the Climate Brochure

For more information on features and specifications.

Where we find out how our solutions accelerate research and how we can adapt to new challenges.

DENSsolutions team members together with customers from FHI Berlin, DTU Nanolab Kgs. Lyngby, ER-C Jülich, EMAT Antwerp, ETH Zürich, Johnson-Matthey Didcot, University of Limerick, Trinity College Dublin and Queen’s University Belfast.

A little over 3 years ago, the first Climate in situ gas & heating systems were installed by DENSsolutions at customer sites. Therefore, the time has come to evaluate the results obtained so far by all our European customers and to share experiences. A 2-day meeting was held in Delft, the Netherlands on 5th & 6th June 2019 to provide an open forum for both users and the DENSsolutions team to share their results and suggestions.

Dr. Michele Conroy and Dr. Jennifer Cookman from the University of Limerick sharing their future plans for Climate experiments.

Presentations and discussions

Each Climate user gave a presentation on: their in situ gas & heating research, other research using the Climate system in their departments, and plans for future research.The topics covered included catalyst research on nano-particles, carbon nano-tube growth, and materials science on lamella-type samples. Our team members also gave presentations on our latest product development and newest applications.

Dr. Armand Beche (center) from EMAT Antwerp

Dr. Xing Huang (right) from ETH Zurich

We value the experience and feedback that our users from different institutes and companies, as well as DENSsolutions team members, brought to the discussions. Our discussions were dynamic and covered not only in situ TEM but also experiments that used the Climate Nano-Reactor in other environments such as a Beamline or an X-ray microscope.

Dr. Manfred Schuster from Johnson Matthey sharing insights from their customized beamline experiment

During the conference, new ideas, theories and product feedback were shared so we left with a list of possible improvements for our solutions as needed by the people who use them. These included: ease-of-use items, improvements on MEMS chips, tools to improve sample drop casting, and ideas on how to improve gas & heating control.

Dr. Thomas Hansen DTU explaining on the importance of low dose imaging.

Continuing the conversation

All the participants agreed that we should continue these discussions to improve both in situ TEM research and the tools that facilitate it. DENSsolutions will enable these conversations as part of an online environment as well as by organizing new Climate user meetings. Furthermore we see possibilities to organize forums like this in the future for other products and for users from other regions.

Ronald Marx MSc, DENSsolutions

Our Climate Product Manager Ronald Marx commented at the end of the 2-day meeting:

“It was a great pleasure for me to host all these Climate users in Delft and engage in discussions that reveal both the current and the potential new benefits of doing in situ research with the system’.

Interested in the Climate system?

Download the Climate Brochure

For more information on features and specifications.