| Deposition status can be observed inside the equipment
| Real-time determination of thin film material concentration and crystal structure
| Used in semiconductors, OLED, batteries, electrode materials, etc.


Thin film deposition is one of the semiconductor processes that gradually deposits thin layers on a silicon wafer.

Thin films play a role in separating, connecting, and protecting semiconductor circuits. Therefore, semiconductor quality is improved when the thin film is formed as thinly and uniformly as possible.

However, since the thickness is less than 1 micrometer (㎛), implementing it is a process with high technical difficulty, and for this reason, it is important to measure and check the thin film formation status on a regular basis.

The Korea Institute of Industrial Technology (KITECH) has succeeded in developing a real-time deposition film measurement system for chemical vapor deposition materials that can observe, measure, and analyze the entire process of forming a thin film on a wafer inside chemical vapor deposition equipment in real time.

Chemical vapor deposition is a chemical deposition method that uses the chemical reaction of gases to deposit a thin film in the form of vapor, and is mainly used in semiconductor processes.

In the past, to check whether the thin film was properly deposited, the thin film had to be removed from the equipment and tested with a separate analysis device. However, in the process, the thin film could deteriorate due to contact with oxygen or moisture in the air, which could damage the reliability of the analysis results, and if a defect occurred in the thin film, it was difficult to determine the cause.

Dr. Heo Hoon's research team at the High Temperature Energy Systems Group of the Korea Institute of Science and Technology (KIST) solved this problem by installing an in-situ (=within a container) Raman spectroscopy device that can measure and analyze the deposition process of thin film materials inside chemical vapor deposition equipment.

The installed in-situ Raman spectroscopy device is based on the Raman effect, which occurs when monochromatic light is shined on a gas, transparent liquid, or solid, and light with a slightly different wavelength is generated in the scattered light.

By utilizing the Raman spectrum, which is a special arrangement of light generated by the Raman effect, various physical properties such as the concentration, crystal structure, and crystallinity of thin film materials can be identified in real time right inside the equipment. In addition, various variables such as compounds and reaction gases required for chemical deposition, and thin film growth temperature and time can be measured and analyzed to optimize the process.

The research team also developed an analysis technique that can infer permittivity based on the results of thin film material properties analysis. Permittivity refers to the degree to which an object becomes electrically charged when electrically charged molecules are aligned when an electric field is applied. The results of the dielectric constant analysis are used to develop semiconductor materials with low dielectric constant characteristics that are advantageous for high integration and high speed implementation.

The research team succeeded in depositing low-k semiconductor materials using the constructed system and analyzing the changes in physical properties according to the process and processing conditions in real time using Raman spectra, thereby increasing the possibility of developing new thin film materials.

Dr. Heo Hoon said, “This is a case in which the limitations of the existing ex-situ (=outside the container) thin film analysis method were overcome with domestic technology, so it will be able to contribute to the localization of related materials and equipment,” and “It can be used in various fields such as not only semiconductors but also OLED materials, secondary batteries, or electrode materials for solar cells.”

Meanwhile, Saenggangwon is promoting the commercialization of a real-time deposition film measurement system together with semiconductor material companies.