World's First Development of Semiconductor Process Plasma Measurement Sensor

Korea Research Institute of Standards and Science "Helps Improve Semiconductor-Display Equipment Yield"

Senior Researcher Hyochang Lee of KRISS (left) is conducting a plasma experiment. Photo by Korea Research Institute of Standards and Science (KRISS)

[Asia Economy Reporter Kim Bong-su] The Korea Research Institute of Standards and Science (KRISS) announced on the 31st that it has developed the world's first sensor capable of measuring the amount of plasma used in semiconductor and display processes in real time. Since it can be used without stopping the operating equipment, it is expected to help improve the performance evaluation of semiconductor and display equipment as well as product yield.

This technology is based on a Korean original patent registration, and patent applications have been completed in four countries including the United States, Europe, China, and Japan. The KRISS research team plans to develop 'intelligent etching process equipment' with the sensor embedded in the device.

With the low power consumption, ultra-fine linewidth, and three-dimensional structuring of semiconductor devices, the difficulty of semiconductor plasma processes is increasing. Plasma processes are used in the etching process, which removes unnecessary parts while leaving only the necessary parts of the semiconductor circuit pattern.

The stability of the etching process leads to yield, which is a measure of semiconductor productivity and profitability. If the circuit parts are broken or uneven due to incorrect etching, errors occur in the produced semiconductor chips, and they cannot perform the desired operations.

Until now, there has been no sensor capable of directly measuring plasma variables in the wafer area during the process. Although sensors used exclusively in mass production processes overseas exist, they use indirect measurement methods that measure the wafer's temperature or voltage uniformity.

Indirect measurement sensors require stopping the process and inserting the sensor for measurement, making it difficult to detect process abnormalities in real time. After insertion, a long time is needed to normalize the process environment, often reducing semiconductor yield.

The research team has developed the world's first density measurement technology that can directly measure plasma variables. This technology can measure plasma density values and uniformity, which directly affect wafer process results, in real time, with a measurement uncertainty within 2%, the highest level in the world.

For sensor development, the research team selected structures such as point-type, ring-type, and bar-type, and through theoretical calculations and experiments on signal sensitivity and self-resonance characteristics, derived the bar-type flat sensor as the optimal structure. Subsequently, through planar probe experiments, electromagnetic field simulations, and circuit model development, the sensor's measurement reliability was comprehensively evaluated.

Senior Researcher Lee Hyo-chang of KRISS said, "The sensor developed this time is practical as it can be installed in desired parts such as the electrostatic chuck at the bottom of the wafer, edge ring, and chamber wall," adding, "In the future, through the establishment of standard test procedures for related technologies, it is expected to be used as plasma measurement standard equipment that can verify the performance of semiconductor and display materials, parts, and equipment."

The research results were published in the international academic journal in the field of plasma science, Plasma Sources Science and Technology.

Meanwhile, in May, Senior Researcher Lee Hyo-chang was recognized for his contributions to plasma measurement science research and received the Noah Hershkowitz Early Career Award from the European Physical Society, which is awarded to only one person annually. He was also appointed to the Editorial Board of the Plasma Sources Science and Technology journal.

This content was produced with the assistance of AI translation services.