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Park J, Choi Y, Kwon S, Lee Y, Kim J, Kim JJ, Lee J, Ahn J, Kwak H, Yang Y, Jo T, Lee M, Kim K. Microsphere-assisted hyperspectral imaging: super-resolution, non-destructive metrology for semiconductor devices. LIGHT, SCIENCE & APPLICATIONS 2024; 13:122. [PMID: 38806499 PMCID: PMC11133334 DOI: 10.1038/s41377-024-01469-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 04/18/2024] [Accepted: 05/07/2024] [Indexed: 05/30/2024]
Abstract
As semiconductor devices shrink and their manufacturing processes advance, accurately measuring in-cell critical dimensions (CD) becomes increasingly crucial. Traditional test element group (TEG) measurements are becoming inadequate for representing the fine, repetitive patterns in cell blocks. Conventional non-destructive metrology technologies like optical critical dimension (OCD) are limited due to their large spot diameter of approximately 25 μm, which impedes their efficacy for detailed in-cell structural analysis. Consequently, there is a pressing need for small-spot and non-destructive metrology methods. To address this limitation, we demonstrate a microsphere-assisted hyperspectral imaging (MAHSI) system, specifically designed for small spot optical metrology with super-resolution. Utilizing microsphere-assisted super-resolution imaging, this system achieves an optical resolution of 66 nm within a field of view of 5.6 μm × 5.6 μm. This approach effectively breaks the diffraction limit, significantly enhancing the magnification of the system. The MAHSI system incorporating hyperspectral imaging with a wavelength range of 400-790 nm, enables the capture of the reflection spectrum at each camera pixel. The achieved pixel resolution, which is equivalent to the measuring spot size, is 14.4 nm/pixel and the magnification is 450X. The MAHSI system enables measurement of local uniformity in critical areas like corners and edges of DRAM cell blocks, areas previously challenging to inspect with conventional OCD methods. To our knowledge, this approach represents the first global implementation of microsphere-assisted hyperspectral imaging to address the metrology challenges in complex 3D structures of semiconductor devices.
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Affiliation(s)
- Jangryul Park
- Metrology and Inspection Equipment R&D Team, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Youngsun Choi
- Metrology and Inspection Equipment R&D Team, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Soonyang Kwon
- Metrology and Inspection Equipment R&D Team, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Youngjun Lee
- Metrology and Inspection Equipment R&D Team, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Jiwoong Kim
- Metrology and Inspection Equipment R&D Team, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Jae-Joon Kim
- Process Development Department, DRAM Process Development Team, Semiconductor R&D Center, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Jihye Lee
- Process Development Department, DRAM Process Development Team, Semiconductor R&D Center, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Jeongho Ahn
- Process Development Department, DRAM Process Development Team, Semiconductor R&D Center, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Hidong Kwak
- Process Development Department, Semiconductor R&D Center, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Yusin Yang
- Process Development Department, Semiconductor R&D Center, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Taeyong Jo
- Metrology and Inspection Equipment R&D Team, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Myungjun Lee
- Metrology and Inspection Equipment R&D Team, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Kwangrak Kim
- Metrology and Inspection Equipment R&D Team, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, hwaseong-si, Gyeonggi-do, 18848, Republic of Korea.
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Kwon S, Park J, Kim K, Cho Y, Lee M. Microsphere-assisted, nanospot, non-destructive metrology for semiconductor devices. LIGHT, SCIENCE & APPLICATIONS 2022; 11:32. [PMID: 35132060 PMCID: PMC8821559 DOI: 10.1038/s41377-022-00720-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 12/28/2021] [Accepted: 01/17/2022] [Indexed: 05/25/2023]
Abstract
As smaller structures are being increasingly adopted in the semiconductor industry, the performance of memory and logic devices is being continuously improved with innovative 3D integration schemes as well as shrinking and stacking strategies. Owing to the increasing complexity of the design architectures, optical metrology techniques including spectroscopic ellipsometry (SE) and reflectometry have been widely used for efficient process development and yield ramp-up due to the capability of 3D structure measurements. However, there has been an increasing demand for a significant reduction in the physical spot diameter used in the SE technique; the spot diameter should be at least 10 times smaller than the cell dimension (~30 × 40 μm2) of typical dynamic random-access memory to be able to measure in-cell critical dimension (CD) variations. To this end, this study demonstrates a novel spectrum measurement system that utilizes the microsphere-assisted super-resolution effect, achieving extremely small spot spectral metrology by reducing the spot diameter to ~210 nm, while maintaining a sufficiently high signal-to-noise ratio. In addition, a geometric model is introduced for the microsphere-based spectral metrology system that can calculate the virtual image plane magnification and depth of focus, providing the optimal distance between the objective lens, microsphere, and sample to achieve the best possible imaging quality. The proof of concept was fully verified through both simulations and experiments for various samples. Thus, owing to its ultra-small spot metrology capability, this technique has great potential for solving the current metrology challenge of monitoring in-cell CD variations in advanced logic and memory devices.
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Affiliation(s)
- Soonyang Kwon
- Equipment R&D Team 4, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Jangryul Park
- Equipment R&D Team 4, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Kwangrak Kim
- Equipment R&D Team 4, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Yunje Cho
- Equipment R&D Team 4, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do, 18848, Republic of Korea
| | - Myungjun Lee
- Equipment R&D Team 4, Mechatronics Research, Samsung Electronics Co., Ltd., 1-1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do, 18848, Republic of Korea.
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