Unveiling the Restrictions of Japan’s Semiconductor Ban

On March 31st, 2023, the Japanese Ministry of Economy, Trade and Industry (METI) proposed a plan to “add 23 categories of advanced semiconductor production equipment to the list of items prohibited for export”. The plan includes a revision of the ordinance in May of this year, with the official implementation in July. Currently, the plan is in the public comment collection stage.

When Japanese companies export semiconductor equipment to regions and countries outside the scope of the “General License” for allied and friendly countries, they must apply for and obtain government approval separately. At a press conference on the same day, Minister of Economy, Trade and Industry, Hiroshi Kajiyama, stated clearly that “this is not an ordinance targeting a specific country,” “this is not an ordinance following the footsteps of the United States,” and “it is not a complete ban on exports. If it is confirmed that the export target has no potential military use, the export license can also be granted.” However, the minister’s statement clearly did not receive the approval of the relevant personnel. According to the Japanese Ministry of Economy, Trade and Industry, ten advanced semiconductor production equipment manufacturers and testing equipment manufacturers, including Tokyo Electron, Nikon, SCREEN, and Lasertec, will be affected by this ordinance. The impact on Japanese semiconductor equipment manufacturers is “very slight” (METI). Japanese semiconductor production equipment manufacturers have already begun to investigate in detail which equipment belongs to the restricted range and how it will affect their performance.

However, some have pointed out that the legal documents from the Japanese Ministry of Economy, Trade and Industry are difficult to understand. Although the documents cover detailed technical details, they are obscure and also include some non-advanced technology-related content.

Therefore, I classified the 23 types of equipment (actually 30 categories, including not only equipment but also pellicle-related items in the semiconductor process) according to the semiconductor process. The order of the categories in this article is different from that of the Japanese Ministry of Economy, Trade and Industry’s records.

Heat treatment-related (Category 1)

Annealing equipment for reflow of copper (Cu), cobalt (Co), and tungsten (W) (any one of these elements) in a vacuum state below 0.01 Pa.

Inspection equipment (Category 1)

Inspection equipment for EUV exposure direction mask blanks or masks with circuits. (Category 1)

Exposure-related equipment (Category 4)

1. Pellicles for EUV exposure.
2. Production equipment for pellicles used in EUV exposure.
3. Coater developer equipment for EUV photoresist coating and development.
4. Stepper and scanner lithography equipment for wafer processing with a light source wavelength of 193 nanometers or above, and a numerical aperture multiplied by the light source wavelength and divided by 0.25 that gives a value of 45 or below. (According to the author’s calculation, Nikon’s ArF immersion exposure equipment falls under the scope of this regulation, while exposure equipment before the dry ArF process is not included.)

Equipment for dry cleaning, equipment for wet cleaning (Category 3)

1. Equipment that forms a copper film while removing polymer residue and copper oxide film in a vacuum state of less than 0.01Pa.
2. Multi-chamber equipment is used for dry etching in the pre-treatment process of removing the oxide film on the wafer surface.
3. Single-wafer wet cleaning equipment (with drying after modifying the surface properties of the wafer).

Etching (Category 3)

1. Equipment belonging to the category of isotropic etching with a selectivity ratio of 100 or more for silicon-germanium (SiGe) and silicon (Si), and equipment belonging to the category of anisotropic etching with a high-frequency pulse output power supply, a high-speed switching valve with a switching time of fewer than 300 milliseconds, and an electrostatic chuck.
2. Wet etching equipment with a selectivity ratio of 100 or more for silicon-germanium (SiGe) and silicon (Si).
3. Equipment belonging to the category of anisotropic etching, where the ratio of etch depth to etch width is greater than 30 for etching dielectric materials, and the etching width is less than 100 nanometers. The equipment includes a high-speed pulse output power supply and a high-speed switching valve with a switching time of fewer than 300 milliseconds.

Film deposition equipment (Category 11)

1. Here are various types of film deposition equipment. *Equipment that uses electroplating to form cobalt (Co) films.

• Equipment for forming cobalt (Co) films using electroplating.
• CVD equipment that uses bottom-up deposition techniques to fill gaps or seams with cobalt (Co) or tungsten (W) with a maximum size of 3 nanometers.
• Multi-process equipment that forms metal contact layers (films) in the same chamber, plasma equipment that uses hydrogen (or hydrogen, nitrogen, and ammonia mixtures), and equipment that uses organic compounds to form tungsten (W) films while maintaining wafer temperatures between 100 and 500 degrees Celsius.
• Multi-chambered film deposition equipment that can maintain a vacuum state of 0.01 Pa or less (or an inert environment) and can process multiple processes, including the following metal contact layer film deposition processes:
  1. Forming titanium nitride or tungsten carbide layers using organic metal compounds while maintaining wafer temperatures between 20 and 500 degrees Celsius.
  2. Forming cobalt (Co) layers using sputtering processes while maintaining wafer temperatures below 500 degrees Celsius and pressures between 0.1333 Pa to 13.33 Pa.
  3. Forming cobalt (Co) layers using organic metal compounds while maintaining wafer temperatures between 20 and 500 degrees Celsius and pressures between 133.3 Pa to 13.33 kPa.
• Equipment for forming copper wiring using the following processes:
  1. Forming cobalt (Co) or ruthenium (Ru) layers using organic metal compounds while maintaining wafer temperatures between 20 and 500 degrees Celsius and pressures between 133.3 Pa to 13.33 kPa.
  2. Forming copper (Cu) layers using PVD technology while maintaining wafer temperatures below 500 degrees Celsius and pressures between 0.1333 Pa to 13.33 Pa.
• ALD equipment uses metal-organic compounds to selectively form barrier layers or liners.
• ALD equipment for filling gaps between insulation films without producing gaps (with a width-to-depth ratio greater than 5 and a gap width of 40 nanometers or less) by filling with tungsten (W) or cobalt (Co) while maintaining wafer temperatures below 500 degrees Celsius.

2. Equipment for selectively growing tungsten (W) or molybdenum (Mo) films without using a barrier layer (Barrier) under a vacuum state of less than 0.01 Pa (or in an inert environment).
3. Equipment for forming ruthenium (Ru) films using organometallic compounds while maintaining a wafer temperature of 20 to 500 degrees Celsius.
4. “Atomic Layer Deposition Equipment (limited to equipment that supports and rotates axis wafers)”, all of the following are within the scope of restrictions: (1) using plasma to form atomic layer films. (2) equipped with a plasma source. (3) having a “plasma shield” or related technique for enclosing plasma in the plasma irradiation area.
5. All equipment capable of forming silicon (Si) or carbon (C) films at temperatures between 400 and 650 degrees Celsius or using free radicals generated in other spaces (not in the same space as the wafer) to form thin films are within the scope of restricted exports. The following criteria apply: (1) the relative dielectric constant is less than 5.3. (2) the ratio of the partial size of the horizontal aperture to the depth of the line for lines with a size less than 70 nanometers exceeds five times. (3) the pitch of the line is less than 100 nanometers.
6. Equipment for forming multilayer reflection films (used as masks for extreme ultraviolet integrated circuit manufacturing equipment) using ion beam deposition or physical vapor deposition (PVD) processes.
7. All equipment used for the epitaxial growth of silicon (Si) or silicon-germanium (SiGe) (including carbon-doped materials) is within the scope of control. The following criteria apply (1) equipment with multiple chambers that can maintain a vacuum state of less than 0.01 Pa (or an inert environment with a water and oxygen partial pressure below 0.01 Pa) between multiple processes. (2) equipment with a chamber designed to purify the wafer surface for use in the front-end semiconductor process. (3) equipment with an epitaxial growth working temperature below 685 degrees Celsius.
8. Equipment capable of forming a carbon hard mask with a thickness greater than 100 nanometers and a stress of fewer than 450 MPa using plasma technology.
9. Equipment capable of forming tungsten (W) films using atomic layer deposition or chemical vapor deposition (limited to less than 10^19 fluorine atoms per cubic centimeter).
10. Plasma deposition equipment for forming low dielectric layer films with a relative dielectric constant of less than 3.3 to prevent gaps from forming between metal lines (limited to widths less than 25 nanometers and depths greater than 50 nanometers).
11. Annealing equipment operating under a vacuum state of less than 0.01 Pa, is used to minimize or eliminate gaps or joints in copper (Cu), cobalt (Co), and tungsten (W) lines through reflow.

Words in the end

According to a report by Nikkei, a senior official at a major Japanese semiconductor manufacturing equipment company expressed confusion regarding the recent announcement, stating that “we have come up with various ideas, but it is harder to understand than expected.” Lasertec, which produces inspection equipment for “EUV exposure” used in ultrafine processing, also noted that there are still unclear aspects regarding how to operate the equipment and that they will collect information from relevant government agencies and industry groups to take appropriate measures.

Nobunaga Naganuma of UK research firm Omdia commented, “Each company has different business models, and it is a very complicated task to investigate whether the equipment is being used for cutting-edge products,” and suggested that “Japanese manufacturers may stop business based on their own judgment.”

Given Japan’s influence in the equipment industry, the impact of this restriction is worthy of our close attention.