Atonarp, a Tokyo-based startup with a Silicon Valley base of operations, has released a compact mass spectrometer for in-situ monitoring of semiconductor manufacturing equipment. The device can analyze process gases during etching and deposition in the chamber of semiconductor manufacturing equipment and provide real-time analysis information as feedback. This could be one of the basic technologies for smart manufacturing, so to speak.

Atonarp ASTON
Figure 1 Atonarp's compact mass spectrometer Aston Source: Atonarp

Smart manufacturing or Digital Transformation (DX) in manufacturing is required in various manufacturing sites. This is to increase production efficiency. In semiconductor manufacturing as well, improving manufacturing yield and production efficiency through DX can be a powerful means of reducing costs. One of these is the optimization of manufacturing conditions based on an understanding of the current status of manufacturing equipment (equipment health check).

For example, in manufacturing equipment for etching and deposition, it will be possible to prevent loading effects in real time, which can cause wafer-to-wafer variation as material generated by the plasma adheres to or is scraped off the chamber walls. It will be possible to reduce wafer-to-wafer variation and lot-to-lot (Foup box) variation. To do this, we need to know in-situ the "health status" in the equipment.

Semiconductor processes are becoming more complex, especially with FinFETs, gate-all-around (GAA) structures, and high aspect ratios in 3D-NAND, while miniaturization is progressing, so small variations can easily lead to large process fluctuations. Therefore, EPCO (Equipment and Process Co-Optimization) is required these days, and more precise measurement tools and in-situ monitoring are becoming important.

To do this, it is necessary to use AI (machine learning) to find the correlation between actual data and the input/output data of the machine learning model. The actual data is acquired in-situ and the analysis by AI is done on a cloud-based basis to optimize the semiconductor process using DX in the future.

The new compact mass spectrometer Aston (Figure 2) from Atonarp is a device for in-situ detection and analysis of substances generated in the chambers of manufacturing equipment. By analyzing substances, it is possible, for example, to detect endpoints in etching, detect leaks in the chamber, and make adjustments prior to mass production. The basis of mass spectrometry is the quadrupole analyzer method, but it is all about extracting ions using electrodes equipped with hyperbolic curved surfaces using electrical discharge machining technology.

The key to the mass spectrometer Aston is plasma ionization technology and self-cleaning technology Source: Atonarp

Figure 2: Plasma ionization technology and self-cleaning technology are the keys to the mass spectrometer Aston Source: Atonarp

In conventional mass spectrometers, the filament in the detector chamber is degraded by highly reactive etching gases (NF3, CF4, Cl2, etc.) during the etching process, shortening its life, but Aston has developed a technology that uses plasma to ionize, eliminating the need for a filament. Here, the company claims that the substance to be detected is ionized by vibrating it with an RF circuit and making it resonate with molecular vibrations.

They also introduced a self-cleaning technology called ReGen, which generates plasma ions to remove reactants deposited in the chamber. Using these two technologies, the company has succeeded in operating the sensor's sensitivity for hundreds of hours at MTBC (Mean Time Between Cleans) without loss of sensitivity.

The company is funded not only by Silicon Valley venture capitalists, but also by Japan's INCJ (Innovation Network Corporation of Japan), life science firm Nipro, and financial firms SBI Holdings and Furukawa Electric. The company is focusing on two products: mass spectrometers for semiconductor manufacturing and optical spectrometers for life science. The company recently succeeded in obtaining a $50 million Series D financing, bringing the total investment to $110 million. Prakash Murthy, the founder, president, and CEO of this unique startup company, resides in Tokyo, Japan.