On-Site Hydrogen Solutions: Smart, Reliable, and Flexible
Hydrogen in Electronics
Hydrogen (H2) is a commonly used gas in various steps of semiconductor manufacturing. It is used as a co-reactant in deposition and etch processes, for surface passivation, and for cleaning. One of the major uses of hydrogen is in epitaxial deposition of silicon to form the n and p wells in the transistor. With the advent of 3D transistors, there has been an increase in the number and thickness of epitaxial Si, Si-C, and Si-Ge layers. Another potential source of H2 consumption is EUV, which requires a large continuous flow of H2 in order to maintain a reducing atmosphere in the source.
There has also been a trend to build larger fabs in clusters at a single site to enable greater economies of scale. Together, these factors have greatly increased the demand for hydrogen at semiconductor fab sites.
Typically hydrogen has been delivered in two forms: compressed gas in tube trailers or liquid hydrogen. The latter has been the preferred means of delivery in the U.S. and Europe since higher volumes can be delivered each time. However, transportation regulations in Asia prevent liquid hydrogen transport by road and there tube trailers are more commonly used.
Once the consumption of hydrogen exceeds 50m3/hr, it may be more economical to put a generator on the customer site. Linde offers a wide range of on-site H2 generators.
Hydrogen On-Site Solutions by Linde ECOVAR®
On-site supply solutions, including those to the electronics industry, fall under the Linde ECOVAR umbrella. All three main industrial gases—nitrogen, oxygen, and hydrogen—are represented within the ECOVAR portfolio. The portfolio gas generators/plants produce products over a wide range of flow, pressure, and purity to meet the most stringent customer demands.
- Steam methane reforming (SMR)
- Methanol cracking
All three technologies require additional gas purification steps to remove impurities. These impurities are either created in the hydrogen generation process as by-products or are carried into the process by the feed gases themselves. Product hydrogen purities can range from 99.9% to 99.999% and can be achieved through the use of conventional pressure swing adsorption purifiers.
Choice of technology depends on a number of factors:
- Customer preference
- Cost and availability of electricity and feed stocks
In general, electrolysis will be used for low flows <200 Nm3/h and where power costs are low. Application of the methanol cracker technology is limited to geographic regions where stability of methanol feed stock pricing is achieved through subsidy. SMR technology is the most common means of hydrogen production due to the wide and increasing availability of low-cost natural gas.
Hydroprime™ HC300: Small-Scale SMR for Cost-Efficient Hydrogen Production
With the demand for secure on-site supply of high-quality hydrogen growing and with the availability of low-cost natural gas increasing, the development of a small-scale, standardized, skid-mounted SMR unit was what Linde had in mind to meet the market demand when it introduced the Hydroprime product line.
Within Linde, a development initiative was started in 2009 that incorporated cutting-edge design ideas with latest commercially available technology. Since inception, ECOVAR, HydroChem, and HYCO operations divisions have combined resources and best practices, which resulted in the design available to the market today. Currently, there are several of these plants, located throughout Europe and Asia, which reliably and safely serve a wide range of markets.
The Hydroprime HC300 can produce 330 Nm3/h of hydrogen at 14 barg and with a purity of 99.999%.
Since these plants are skid mounted, multiple units can easily be connected in parallel to meet a wide product flow range.
The HC300 plant footprint is 14 L x 3 W x 4 H meters. It is delivered to a customer’s site after a full factory authorization (cold test) to insure ease of field installation and to reduce commissioning time and costs.
A typical Hydroprime installation consists of the hydrogen plant, ancillary utility systems, and a backup system that consists of either tube trailers or liquid hydrogen with vaporization. At sites where merchant product is too far for reliable supply for the backup, a redundant HC300 plant can be installed. Linde plants are monitored 24 / 7 via a remote operations center for quick response to plant issues and to insure uninterrupted product supply.
The development of the Hydroprime has resulted in a low-cost, reliable, flexible hydrogen supply solution that is a good alternative for the more established supply forms like electrolysers, tube trailers, or liquid hydrogen.
This blog post was contributed by Tony Moes, Head of Linde ECOVAR – Standard Plants, Global Business Unit Tonnage. For more information, contact Francesca Brava: email@example.com.