Vacuum Pump Systems For Manufacturers Of Microelectronic Devices, Including Semiconductors

Lithography, patterning of the wafers, is a critical step in the semiconductor process. Although conventional and even immersion lithography generally do not require vacuum environments, extreme ultraviolet (EUV) lithography and electron beam (e-beam) lithography do require vacuum pumps. Edwards has you covered for both of these applications.

EUV Lithography Pumping Solutions
Multi-patterning techniques have their place, but the future will likely require the use of EUV lithography due to the extremely short wavelength of light EUV systems deliver. The vacuum environment is absolutely critical for optimum performance of your system. Cleanliness of the vacuum system is particularly important and helps to extend service intervals. We have worked with EUV Lithography OEMs and light-source OEMs to develop precision vacuum systems that deliver the maximum reliability for the large investment you make.

E-Beam Lithography Solutions
E-beam lithography has an important role to play in patterning of silicon wafers. Clean vacuum with low vibration is essential to ensure precision and high up-time of your system.

Our Product Solutions
You will likely require a turbomolecular pump (TMP) to deliver the ultra-high vacuum on your process tool. Our STP range of TMPs have fully magnetically-levitated rotors to reduce the risk of contamination to the chamber and extend service intervals. Today’s products have been developed to reduce total costs and footprint through integration of the controller into the pump itself, removing the need for an external controller and hefty control cable between the controller and pump.

Chemical vapour deposition (CVD) systems come in a variety of configurations to deposit numerous types of films. The processes also operate at different pressures and flow regimes, many using fluorine-containing dry clean processes. All of these variables mean you will want to consult with one of our application engineers to select the right pump and gas abatement system to maximise our product’s service interval and increase the up-time of your process.

Dry Pump Selection
CVD processes generally have four specific challenges to overcome that will drive your dry pump product selection. These challenges are:

Powder
Many processes can generate large amounts of powder by-product. The vacuum pump needs to be designed to handle this powder without seizing. In some cases, the powder may actually be sticky or require high temperature operation to ensure that other by-products entrained in the powders do not condense inside the pump and jam the mechanism. For nearly all powder-producing processes, you will be driven toward using a pump employing a high-torque motor to be sure that the pump keeps rotating under stress.

Condensation
Some of the by-products of the semiconductor process contain gases that will change from gas phase to solid phase as the partial pressure of the gas increases, or the material comes in contact with cold surfaces. When pumping these by-products, you will need a very hot pump and, preferably, a pump that has a uniform temperature profile from inlet to outlet as much as possible.

Corrosion
Some processes will require the pumping of halides. In particular, fluorine-containing cleaning processes will be required to maintain the cleanliness of your chamber, but the activated fluorine radicals can attack the internal surfaces of the pump.  If the process is mostly using chemicals that can corrode the pump, you will want to be sure that the pump temperature can be set to a low value to reduce the risk of corrosion. Our pumps are designed with selectable temperature set points and high rotational speeds to reduce the risk of corrosion and reduce the overall rate of inevitable material loss that can occur within the pump. For some CVD processes, a balance is struck with the temperature set point to be sure that any condensation issues are avoided without undue rates of corrosion.

Metal Plating
Some of today’s processes use metal-organic precursors that, as they pass through the chamber, can result in by-products that have a high risk of depositing their metal contents onto the pump surfaces. A low temperature pump is usually best to ensure long service intervals for these applications. 

Gas Abatement Selection
Every CVD process will require some form of gas abatement device so that the toxic and dangerous by-products of the process can be safely converted into disposable elements. We pride ourselves on our fuel-fired exhaust gas management devices because of their ability to efficiently force recombination of the by-products into safe compounds. Being fuel-fired with multiple-inlet capability, you can get rapid deployment of Green Mode by turning off the main burner when you do not need to abate your process exhaust. 

Integrated Systems and Sub-Fab Solutions
With just a pump and a gas abatement device, you still are not ready to run your process. You will need to connect the pump exhaust, connect up your line heaters where required, run your water, purge and electrical lines, and then get all of your control signals ready. You will also have to consider double-enclosure, gas leak detection, and how you want to conduct leak checks after your tool maintenance. All of these things will cost you design time and money. We understand the problem so we have developed integrated, process-specific solutions. 

Our integrated systems are already pre-designed for most semiconductor CVD processes. The exhaust heaters are set for the correct temperature to minimize cost and maximise up-time. We put leak check ports and gate valves where they are required. We can mount toxic gas sensors within the unit and get the whole system enclosed and, most importantly, you only need to provide one of each of the required utilities. We distribute the purge, water, electricity, and control signals where they are needed and create a ready-to-go system. 

All of our integrated systems have been designed based on global experience. We are leaders in vacuum and abatement, so we know what works. We constantly innovate and improve what we do because you demand excellence from Edwards. 

Fleet Management

With all of our equipment deployed in your fab, you will want to know what’s going on all of the time. You want to know if any product is in trouble or in need of maintenance. To answer this question, we offer our FabWorks computer monitoring system. 

The FabWorks system can use Ethernet connectivity to all of our products to constantly retrieve status signals and store them in an automated database. More than tracking trends in such parameters as input power, current, temperature, or purge flow, you also can see warnings or alarms, all of this data can be graphed and exported. With FabWorks you do not need to be in the fab to monitor the equipment, once connected to your intranet, you can be confident you have your finger on the pulse of the sub-fab.

For CVD processing, there will always be products that become stressed and will need maintenance, in worst case scenarios, products can suddenly fail. To prevent unwanted failures, we can work with you and deploy our automated predictive diagnostics models. These models, matched to your process, can provide warnings to you in advance of processing your next batch of wafers so that you can maintain the pump or abatement device and reduce the risk of stoppage mid-process.  

Etch processes have become increasingly complex due to the fine feature size of many semiconductors. Moreover, the proliferation of MEMS devices and 3D structures has increased the use of silicon etch processes for structures with high aspect ratio. Traditionally, etch processes could be grouped into silicon, oxide, and metal categories. The lines between these categories have become blurred with the use of more hard masks and high-k materials being deployed in devices today. Some of the materials used in devices today stubbornly resist vapourising during the etch process leading to deposition within the vacuum components. Today’s processes really have become more challenging than they were several years ago. We keep a close eye on industry and process changes and maintain the pace of product innovation to deliver class-leading performance.

Vacuum Pump Selection
Nearly every dry etch process will require a turbomolecular pump (TMP) to deliver the low pressure you require for your reactive ion etch (RIE) system.  Edwards invented the first TMP and we continue to challenge the industry with new technology and performance. We offer a range of products to match your application requirements. For example, for extremely low pressure, you can use one of our all-bladed TMPs and marvel at the achieved compression ratios and low base pressure. You can select a hybrid product that combines blades and Holweck-designed rotors for high flow operation. We even have products tuned for excellent hydrogen performance because, at molecular speeds, not all molecules behave the same as they travel through the TMP. 

We recognize that space is at a premium so for many of our TMPs we have integrated the controller with the pump. Not only do you no longer need to worry about routing of cumbersome control cables, you save on rack space and spare pump management. We have also developed advanced heating technology to reduce the risk of stubborn gases from sticking to the pump internal surfaces. We have even pioneered new high-emissivity coatings for really difficult applications that need high running temperatures. 

For dry pumps, Edwards will help you select your product to be sure that maximum up-time is achieved. Etch processes can be very challenging to the pump because of the various gases used. For example, will your process be mostly corrosive to the pump, likely to condense within the pump, or neither of these? The process gases you use and the likely by-products need to be considered carefully.  

Gas Abatement Selection
Dry etch processes will require some form of gas abatement to be sure you comply with your local emissions requirements. Moreover, oxide etch, in particular, generates perfluorocarbon (PFC) emissions and you want to be sure that your gas abatement can handle the flow rate of PFCs in your process recipe. PFCs are a known contributor to global warming, so your abatement strategy is important for all of us. Our inward-fired burners are particularly adept at creating a hot flame that can break down the incoming gases and reduce emissions of unwanted chemicals.

Physical vapour deposition (PVD) continues to be an important process in semiconductor manufacturing. Liners and barriers continue to make use of this well established semiconductor process. 

If you are using a cluster tool, you will require a pump for your load-lock chamber and also the transfer chamber. If your PVD tool makes use of cryo pumps, you will also need to prepare a pump to regenerate your cryo pump once it gets full. In many cases, the pump used for the transfer chamber can also be used to regenerate your cryo pump. Many PVD tools used for semiconductor processing deploy cryo pumps. However, increasingly, turbomolecular pumps (TMPs) are used because the TMPs do not need maintenance and they do not need regeneration. These two factors reduce your running costs.

Traditionally, gas abatement is not required for PVD processes. However, if your PVD process tool also includes ALD or CVD chambers, you will need process-ready vacuum pumps and gas abatement. Our application engineers and product specialists will assist you in further information related to these process types and help you determine the optimum size of pump for your system. We can also make recommendations about pipe sizes to help you optimise your PVD system.

Today’s metrology tools represent years of advanced development and continue to play a vital role to high yield and early detection of process deviation. Clean, quiet vacuum is an important enabler to advanced metrology tools. We provide a range of dry pumps and turbomolecular pumps (TMPs) to match your vacuum environment conditions. 

An example of our application of advanced technology is our EPX range of dry pumps. These single-axis pumps rotate at high speeds and can deliver final vacuum pressures up to three orders of magnitude lower than conventional dry pump and booster combinations. In many cases, using one EPX pump can eliminate the need for a TMP.

Another example of clean vacuum is our nXDS range of dry scroll pumps. Edwards’ patented technology makes use of a precision engineered bellows that guarantees that no grease from the bearings can ever outgas into the vacuum space. Moreover, advances in tip seal engineering means significantly extended service intervals.

Ion implant tools still have a significant role to play in front end-of-line processing. The vacuum challenges associated with ion implantation have not become easier with time and we recognise the challenges of operating a vacuum pump in an electrically noisy environment. We are never satisfied by testing for bare minimum conformance to established electromagnetic immunity test standards. We know that pumps used on implant tools will require greater immunity and special design features to be sure that the high voltage sections of the implant tool do not interfere with pump reliability.

We also take particular care in the design of our turbomolecular pumps (TMPs) to be sure that we can provide integrated heating to high temperatures so that maximum reliability is achieved. 

Our application engineers are will help you to select the right products for your implant tool, whether those products are mounted on your tool or beneath your tool in the sub-fab. We want to be sure you experience the quality and reliability you demand from Edwards.

Diffusion, epitaxy, and ALD processes are critical in the manufacture of advanced semiconductor devices. Each of these applications, well understood by Edwards, can represent challenges slightly different to normal CVD processes. Diffusion furnaces will continue to be required as the industry follows Moore’s Law and also if it diverges into More-than-Moore technologies. In general, large capacity pumps are required to provide rapid chamber evacuation, chamber environment exchange, and high throughput capability. 

Epitaxial film deposition equipment continues to be challenging. In many cases, very high flows of hydrogen at low chamber pressures may be required. You will need a reliable pump with high hydrogen gas throughput capability. More than this, you will want to take advantage of our global application experience to be sure that you design your entire vacuum system for safe operation. By-products of the epitaxy processes can be very hazardous and will require special attention for safe operation. 

Atomic Layer Deposition (ALD) processes are becoming more common as device feature size decreases. Whether your system processes wafers one wafer at a time, or in a batch, you will want to use our products that are designed to minimise gas residence time and optimise pump thermal profiles and purge locations to be sure you can achieve the longest service interval possible. ALD processes can be rather challenging.

For all of the diffusion, epitaxy, and ALD processes, we are able to give you the facts to help you select the right gas abatement device. The materials you use in your processes and maximum flow rates will need to be considered in configuring your abatement device.

Where appropriate an integrated system that incorporates our global knowledge and best operating practice should be the preferred solution. Our integrated systems provide excellent value and make managing your process tools much easier via connection to our fab-wide monitoring systems.