R&D Highlights

VOL.5

Semiconductor Manufacturing Equipment and Measures to Protect the Earth's Environment

The current state of the world and the semiconductor equipment industry

Over the years, many countries on our planet have made significant efforts to develop their economies, achieving remarkable advancements in a wide variety of industries. However, the progress came with a great cost to the Earth’s environment. The destruction of nature has occurred frequently as a matter of course, to such an extent that in some regions it would hardly be possible to restore nature. What can we do to prevent further destruction of the Earth’s environment? The existing business model that relies on streamlining the supply of products and services to satisfy the global demand is no longer valid. What we need now is an approach that ensures global conservation of the environment while achieving sustainable business growth.

Let us examine how this applies to semiconductor manufacturing equipment. Assuming all other conditions are equal, semiconductor devices that are manufactured with “green” semiconductor manufacturing equipment are functionally no different from those made by not so ecologically friendly semiconductor manufacturing equipment, which means that consumers will not be disadvantaged by choosing one kind of product over the other. But what about the adverse effects that unmeasured semiconductor manufacturing equipment will have on the Earth’s environment? It is not hard to imagine that the detriments will be felt by all inhabitants of this planet—including those who did not purchase any semiconductor products at all. That should make the issue of global environmental protection a priority for the entire semiconductor industry.

The initiative to curb greenhouse gas emissions is a prime example of global efforts to protect the environment. How national governments should get involved in these efforts is currently being discussed in each country. One of the promising ideas is to impose an environmental tax on the entities that inflict a burden on the environment. Countries such as the U.K., Germany, and Italy have already introduced such a taxation system, aiming to raise public awareness on environmental protection and regulate economic activities accordingly. Similarly, Japan is considering imposing a carbon tax on CO2 emitters. As more governments seek to regulate economic activities in the form of environmental taxes and other means, businesses will have to accept the fact that the single-minded pursuit of efficiency no longer makes good business sense. Our planet is likened to an expansive commons shared by all humanity. If we can release this commons from the spell of the free market economy and spur sustainable growth without damaging the Earth’s environment, the environmental economy will assume a larger share in the overall global economic activities, prompting more countries around the world to embrace environmental protection as the basic premise of their market economy.

The earliest semiconductor devices invented in the late 19th century used natural crystalline minerals. The study of semiconductors made significant progress in the 20th century, resulting in the development and adoption of increasingly sophisticated diodes and transistors. This was followed by the integrated circuit (IC) technology, which enabled multiple transistors to be packed on a small substrate. Since then, the semiconductor industry has been growing at an astonishing rate.

Semiconductor devices are produced by processing silicon using semiconductor manufacturing equipment. The production processes may generate gases with high global warming potentials (GWPs), including CO2, methane, and chlorofluorocarbons. Some processes using plasma or high temperatures can consume significant amounts of electricity, too. That means some advancements in semiconductor technology do affect the Earth’s environment through the associated manufacturing processes. That is why semiconductor device manufacturers today are increasingly calling for high-precision semiconductor manufacturing equipment that also inflicts less burden on the environment. The move clearly reflects the industry’s aforementioned resolve to protect our planet’s environment.

Today, semiconductor devices are found everywhere, embedded in smartphones, cars, game consoles, refrigerators, drones, and countless other products. The cost associated with the environmental protection measures of semiconductor manufacturers is reflected in the pricing of the end-products, and will ultimately be passed on to all of us as the consumers. That is why it is vital for semiconductor equipment manufacturers to reduce the device production cost while minimizing the manufacturing processes’ impact on the environment.

Environmental protection measures by TEL

As a developer, manufacturer, and distributor of semiconductor equipment, Tokyo Electron (TEL) supplies its products to semiconductor device manufacturers throughout the world. With 58 years of history, TEL leads the industry with annual shipments of about 4,000 units of equipment worldwide and cumulative shipments of about 74,000 units. Its products are shipped to many countries besides Japan, including those in North America, Europe, Asia, and the Middle East. As explained earlier, customers in all these countries are now demanding that we develop semiconductor manufacturing equipment that imposes less burden on the environment and can lower the production cost. Given the large number of products already installed at our customers’ sites, it is also necessary for us to offer upgrade options that allow them to keep using the existing equipment while reducing the burden on the environment.

One of the diversified innovations developed by TEL is the technology to control the behavior of particulates in plasma etch processes, which has led to significant reductions in the semiconductor device failure rates (Figure 1). By applying this technology not only to newly released products but also to installed equipment through retrofitting, TEL can provide reduction in the defective output from its equipment, thereby greatly reducing the waste of resources and energy that occurs in the production process.

Figure 1. The number of defects in semiconductor products before and after implementing the particle behavior control technology in a 300 mm plasma etch system.

TEL can provide solutions in reducing the usage of silicon substrates and energy by utilizing machine learning(ML)—a subset of AI technology —to R&D of semiconductors. Figure 2 shows the results of a series of experiments to determine the optimum manufacturing process for low-stress film (target: -100 to 0 MPa) using a plasma-enhanced atomic layer deposition (PEALD) system. Whereas a human engineer conducted about 50 experiments over several weeks and still failed to identify the conditions for depositing desired low-stress film, the machine learning (ML) system arrived at optimal processing conditions in just three experiments. The reduction in the number of experiments minimizes the use of electricity, gases, and silicon substrates, resulting in significant savings of energy and resources.

Figure 2. Exploration of an optimum low-stress film deposition process (target: -100 to 0 MPa) using a 300 mm plasma-enhanced atomic layer deposition (PEALD) system, conducted by a human engineer and a machine learning (ML) system.

By taking the lead in introducing ecologically friendly semiconductor manufacturing equipment to the market, TEL is contributing to the industry-wide effort to mitigate the burden on the earth’s environment. Through all these activities, we believe TEL will contribute more efficiency to the semiconductor production processes while being less taxing to the environment, ultimately reducing the cost incurred by consumers.

As an industry leader, TEL has been actively advocating the importance of reducing the environmental burden associated with semiconductor manufacturing—while also demonstrating its attainments in R&D—at international conferences and other venues. We will continue to work with semiconductor manufacturers throughout the world to establish environmentally sound semiconductor manufacturing processes for the entire industry.

For reference: Academic conference presentation

At the International Symposium on Semiconductor Manufacturing 2018, TEL gave an academic presentation on a subject covered in the present article, receiving the Best Paper Award.

Machine Learning Approaches for Process Optimization
Y. Suzuki, S. Iwashita, T. Sato, H. Yonemichi, H. Moki and T. Moriya
(Tokyo Electron Technology Solutions Ltd.)

References
Kato, Hisatake. 2001. A Primer on the Earth’s Environment. In Japanese. Maruzen Publishing.
Kojima, Hiroyuki. 2006. Economics for Ecologists. In Japanese. Toyo Keizai Shinpo Sha.
Stiglitz, Joseph E., and Walsh, Carl E. 2005. Economics. Japanese translation. Toyo Keizai Shinpo Sha.
Takagi, Yoshiyuki. 1998. Earth Village Declaration. In Japanese. Business-sha.