Part of the  

Solid State Technology

  Network

About  |  Contact

Archive for June, 2015

The Increasing Demand for UHP Nitrogen and the SPECTRA Generator

Thursday, June 25th, 2015

The electronics-related industries are fast moving, with a relentless drive to lower costs and higher performance. One factor that has remained constant throughout this change is the need for high-purity nitrogen for use in almost all of the process steps involved in converting a blank silicon wafer into a set of sellable working semiconductor devices. As the scale of the wafer fabs where these devices are produced has grown from the small and medium sized 6-inch and 8-inch fabs seen in the 1980s and 1990s to the latest wave of 300mm mega fabs, so too have the volumes of nitrogen being used in a particular location.

Typical nitrogen demand at an 8-inch fab in the early 1990s was 3,000 Nm3/hr.  Contrast this with the volumes being consumed now in the latest 300mm fab lines being added to the major campuses of customers, which can now reach as much as 50,000 Nm3/hr or more.

This remarkable progression has been accompanied by a similar growth in the size of the N2 generator plants we have deployed at such fabs, with the capacity of Linde’s SPECTRA-N plant increasing from the 1,000 Nm3/hr size of the first of the series (installed in 1990 in Japan) to the current development of a 55,000 Nm3/hr unit for use in Taiwan.  Throughout this time we have built and installed almost 40 SPECTRA-N plants to serve the semiconductor and TFT-LCD industries. The total combined production capacity of these generators is close to 450,000 Nm3/hr of nitrogen.

The success of the SPECTRA-N is based on three critical factors, which fit closely with the characteristics of the electronics industry: low power consumption, cost-effective capital, and speed of deployment. Having the capability to lead in all three of these dimensions has enabled the SPECTRA-N to become an established benchmark standard for on-site nitrogen generators throughout the industry.

The largest sized plant for the past five years has been the SPECTRA-30000, which can deliver up to 36,000 Nm3/hr of N2 at ultra high purity levels (each impurity below 1ppb), while having the lowest relative power consumption of any such plant in the industry.  This plant has contributed a great deal to the recent successes achieved by our business teams in the U.S. and Asia. SPECTRA-30000 generators have been an integral part of recent major project wins in LCD-TFT fabs in China and new semiconductor wafer fabs in Taiwan and the U.S.

With the strong support of Linde Engineering, we are continuing to drive to ever larger plants to meet the requirements of the latest mega fabs in both semiconductor and TFT-LCD, including ensuring we are prepared for the anticipated jump in nitrogen demand that will come with the introduction of 450mm wafer processing in the next few years.  Linde Engineering has completed the design for the SPECTRA-50000 generator, capable of delivering up to 55,000 Nm3/hr of UHP N2. The first of these plants has been installed in Taiwan and will begin operations in 2015.

The SPECTRA-N generator has been a cornerstone of our success in the electronics market over the past 20 years and one place where this is especially noticeable is Hsinchu in Taiwan.  The first nitrogen plant installed by Linde (then as BOCLH) to serve these early fabs had a capacity of 4,500 Nm3/hr.

As more wafer fabs were built in the Park in the late 1980s and early 1990s, the demand for high purity N2 increased, and BOCLH successfully won contracts to supply the majority of these new fabs and began to install additional nitrogen generators. Deciding to focus on a centralized supply model with a pipeline network to customers was key in building the future success of our electronics gases business in Taiwan. Through the mid 1990s a further three new plants were added, each a SPECTRA-N 5000 generator. A second operating site was established when the first became full, and the pipeline network expanded into new areas of the Park.

This pipeline was designed as a loop and as it developed, it became a series of several interlocking loops which provided more than one pathway for gas to travel from the plants to an individual customer. This ensured a level of redundancy that could prevent a failure in one section from interrupting nitrogen supply. It also allowed the pressures to be balanced across the system to enable optimum power loading to be achieved on the growing network of generators.

By 1998, the total N2 demand in the Hsinchu Park had risen close to 30,000 Nm3/hr and was continuing to grow with more and larger fabs being added by key customers, and particularly the foundries. In order to match the scale of this continuing new fab investment, it was clear that a larger scale of plant was required. In the period from 1998 to 2001, a total of four of our then largest SPECTRA generator – the SPECTRA-N 10000 – were installed, trebling the Hsinchu N2 production capacity.

Following this period of rapid growth, the demand in Hsinchu slowed for a few years; at the same time, the advanced semiconductor production industry was getting started in mainland China with a number of fab projects being invested by Taiwan-related companies. BOCLH was able to make use of one of the earliest of the Hsinchu SPECTRA 5,000 plants by relocating this to Shanghai to capture one of these new fab opportunities there and establish a new operating site and small pipeline grid.

The next phase of Taiwan development took off in 2004, by which time the largest SPECTRA-N plant made was now 15,000 Nm3/hr.  Two of these were installed in Hsinchu taking the total N2 production capacity to above 100,000 Nm3/hr. By now, the primary manufacturers in the Hsinchu Park had begun investing in 300mm wafer fabrication plants, the throughput capacities of which were also growing, further adding to the rate of increase in N2 demand. To keep pace with this, and to take advantage of the lower unit production cost, the first SPECTRA-N 30,000 was installed in Hsinchu in 2007.

In the years since then, the N2 demand has continued to rise, driven largely by the huge amounts of investment made by major customers in adding further 300mm wafer fab capacity in the Park. A second SPECTRA-N 30,000 plant was added in 2011 and in 2014 the largest ever SPECTRA-N generator at 55,000 Nm3/hr was added.

When this begins operations in 2015, it will bring our total production capacity in the Hsinchu Park to 220,000 Nm3/hr of high purity nitrogen, with a total of 15 plants having been installed there in the 27 years of our development of this critical piece of infrastructure. This Hsinchu cluster represents about 10% of advanced global semiconductor manufacturing capacity and Linde is proud of the role that our SPECTRA-N plants have played in supporting its development.

This blog post was contributed by David Pilgrim. For more information, contact Francesca Brava: francesca.brava@linde.com.

On-Site Hydrogen Solutions: Smart, Reliable, and Flexible

Monday, June 1st, 2015

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.

The ECOVAR hydrogen supply solutions are known under the trade name HYDROSS™. They consist of three unique technologies:

  • Steam methane reforming (SMR)
  • Electrolysis
  • 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
  • Flow
  • Purity
  • 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.

One of Linde’s latest HC300 designs, serving the metals market in Austria as of December 2013

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.

In South Korea 4 x HC300 plants are connected side by side. They are supplying high-purity hydrogen to a common hydrogen header.

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: francesca.brava@linde.com.