Spectroscopic Analysis of CF4/O2 Plasma Mixed with N2 for Si3N4 Dry Etching
Source abstract
Abstract
Silicon nitride (Si3N4) etching using CF4/O2 mixed with N2 has become very popular in 3D NAND flash structures. However, studies on Si3N4 dry etching based on optical emission spectroscopy (OES) are lacking; in particular, no study has reported the use of OES for analyzing N2-mixed CF4/O2 plasma. Thus, this study demonstrates an OES-based approach for analyzing a mixed-gas plasma for etching Si3N4 thin films. The state of each single gas plasma of CF4, O2, and N2 as well as that of mixed plasmas of heterogeneous gases CF4/O2, CF4/N2, and O2/N2 was investigated to analyze the mixed-gas plasma. Furthermore, the amount of N2 in the CF4/O2 plasma varied from 0 to 8 sccm. The relationship between the OES analysis results and the Si3N4 etch rate was subsequently established using Si3N4 film etching, and the explanation was verified through a chemical reaction modeling and surface reaction. Therefore, our study confirmed the alteration in chemical species and quantity that occurred when N2 was added to CF4/O2 plasma and the effect of the alteration on Si3N4 etch.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Semiconductor materials and devices · Plasma Diagnostics and Applications · Diamond and Carbon-based Materials Research
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Department of Electronics Engineering, Myongji University, Myongji-ro 116, Yongin-si 17058, Korea
Funding
the National Research Council of Science and Technology under the Plasma E. I. · Korea Institute for Advancement of Technology (KIAT) grant funded by Korea Government (MOTIE)
References (39)
Show source-provided references
1. Silicon Nitride in Semiconductor Device Technology10.4028/www.scientific.net/MSF.47.228 ↗
2. In-Situ Virtual Metrology for the Silicon-Dioxide Etch Rate by using Optical Emission Spectroscopy Data10.3938/jkps.65.168 ↗
3. Plasma Damage on Low-k Dielectric Materials
4. Fourier Transform Infrared Spectroscopy Investigation of Chemical Bonding in Low-k a-SiC: H Thin Films10.1016/j.jnoncrysol.2011.04.001 ↗
5. In-Situ Studies of Interfacial Bonding of High-k Dielectrics for CMOS Beyond 22 nm10.1149/1.2981608 ↗
6. Effect of an In Situ Hydrogen Plasma Pre-Treatment on the Reduction of GaSb Native Oxides Prior to Atomic Layer Deposition10.1016/j.apsusc.2013.04.018 ↗
7. Jang, J., Kim, H.-S., Cho, W., Cho, H., Kim, J., Shim, S.I., Jang, Y., Jeong, J.-H., Son, B.-K., and Kim, D.W. (2009, January 15–17). Vertical Cell Array Using TCAT (Terabit Cell Array Transistor) Technology for Ultra High Density NAND Flash Memory. Proceedings of the Symposium on VLSI Technology, Kyoto, Japan.
8. Deep Neural Network Modeling of Multiple Oxide/Nitride Deposited Dielectric Films for 3D-NAND Flash10.5757/ASCT.2020.29.6.190 ↗
9. Khan, A.H., Srinivasan, S., Choi, J., Athayde, A., and Achutharaman, R. (2014, January 5–9). Etch Challenges for 3D NAND Flash Technology. Proceedings of the ECS and SMEQ Joint International Meeting, Cancun, Mexico.10.1149/MA2014-02/32/1676 ↗
10. Mass Spectrometric Studies of Plasma Etching of Silicon Nitride10.1116/1.582949 ↗
11. Spectroscopic Studies of Fluorescent Emission in Plasma Etching of Silicon Nitride10.1116/1.584398 ↗
12. Silicon Nitride Etching in High- and Low-Density Plasmas using SF6/O2/N2 Mixtures10.1116/1.1547703 ↗
13. Role of NO in Highly Selective SiN/SiO2 and SiN/Si Etching with NF3/O2 Remote Plasma: Experiment and Simulation10.1116/1.5004546 ↗
14. Downstream Etching of Silicon Nitride using Continuous-Wave and Pulsed Remote Plasma Sources Sustained in Ar/NF3/O2 Mixtures10.1116/1.5019673 ↗
15. Prediction of Plasma-Induced Damage Distribution during Silicon Nitride Etching using Advanced Three-Dimensional Voxel Model10.1116/1.4931782 ↗
16. Prévost, E., Cunge, G., De-Buttet, C., Lagrasta, S., Vallier, L., and Petit-Etienne, C. (March, January 26). Study of selective chemical downstream plasma etching of silicon nitride and silicon oxide for advanced patterning applications. Proceedings of the SPIE Advanced Lithography, San Jose, CA, USA.
17. Self-Limiting Reactions of Ammonium Salt in CHF3/O2 Downstream Plasma for Thermal-Cyclic Atomic Layer Etching of Silicon Nitride10.1116/1.5111663 ↗
18. Hsiao, S.N., Nguyen, T.-T.-N., Tsutsumi, T., Ishikawa, K., Sekine, M., and Hori, M. (2020, January 15–16). Etching Characteristics of PECVD-Prepared SiN Films with CF4/D2 and CF4/H2 Plasmas at Different Temperatures. Proceedings of the 2020 International Symposium on Semiconductor Manufacturing (ISSM), Tokyo, Japan.10.1109/ISSM51728.2020.9377537 ↗
19. Hamada, T., Masuda, S., Nishida, K., and Yamamoto, S. (2020). Etching Characteristics of SixNy Film on Textured Single Crystalline Silicon Surface using Ar/CF4 and He/CF4 Surface-Discharge Plasma. Coatings, 10.10.3390/coatings10060563 ↗
20. In-Situ Monitoring of Multiple Oxide/Nitride Dielectric Stack PECVD Deposition Process10.1007/s42341-018-0005-0 ↗
21. Characteristics of a Plasma Information Variable in Phenomenology-Based, Statistically-Tuned Virtual Metrology to Predict Silicon Dioxide Etching Depth10.1016/j.cap.2019.06.001 ↗
22. Use of Optical Emission Spectroscopy to Predict Silicon Nitride Layer Properties10.1016/j.vacuum.2021.110322 ↗
23. Optical Emission Spectroscopy in Low-Temperature Plasmas Containing Argon and Nitrogen: Determination of the Electron Temperature and Density by the Line-Ratio Method10.1088/0022-3727/43/40/403001 ↗
24. Study of Argon Ions Density and Electron Temperature and Density in Magnetron Plasma by Optical Emission Spectroscopy and Collisional-Radiative Model
25. Measurement of Electron Temperature and Density of Atmospheric-Pressure Non-Equilibrium Argon Plasma Examined with Optical Emission Spectroscopy10.35848/1347-4065/abd0c8 ↗
26. Virtual Metrology Modeling of Reactive Ion Etching Based on Statistics-Based and Dynamics-Inspired Spectral Features
27. Etching Characteristics of NF3 and F3NO at Reactive Ion Etching Plasma for Silicon Oxide and Silicon Nitride10.1007/s40042-021-00242-8 ↗
28. Characteristics of Dual-Frequency Capacitively Coupled SF6/O2 Plasma and Plasma Texturing of Multi-Crystalline Silicon10.1088/1674-1056/23/6/065201 ↗
29. SO2 Passivating Chemistry for Silicon Cryogenic Deep Etching10.1088/0963-0252/17/4/045008 ↗
30. Fourier-Transform Infrared and Optical Emission Spectroscopy of CF4/O2/Ar Mixtures in an Inductively Coupled Plasma10.1063/1.1563819 ↗
31. Nitrogen Dissociation in a Low Pressure Cylindrical ICP Discharge Studied by Actinometry and Mass Spectrometry10.1088/0022-3727/38/24/003 ↗
32. Optical Emission Spectroscopy of CF4+O2 Plasmas using a New Technique10.1007/BF01016157 ↗
33. CF and CF2 Actinometry in a CF4/Ar Plasma10.1063/1.350961 ↗
34. Optical Emission Characteristics of Glow Discharge in the N2–H2–Sn(CH3)4 and N2–Ar–Sn(CH3)4 Mixtures10.1016/j.surfcoat.2006.02.013 ↗
35. Experiments and Global Model Analysis of Inductively Coupled CF4/O2/Ar Plasmas10.1143/JJAP.47.8537 ↗
36. Etching Characteristics of Hydrogenated Amorphous Carbon with Different sp2/sp3 Hybridization Ratios in CF4/O2 Plasmas10.1002/ppap.202100075 ↗
37. Actinometry Measurement of Dissociation Degrees of Nitrogen and Oxygen in N2–O2 Microwave Discharge Plasma10.1143/JJAP.49.106101 ↗
38. Fluorination Reaction of Uranium Dioxide in CF4/O2/N2 Rf Plasma10.1016/S0306-4549(03)00039-2 ↗
39. Enhanced Etching of Silicon in CF4-O2-N2 Plasma10.1063/1.103589 ↗