-
Low-temperature inductively coupled radio-frequency plasma is a key plasma source in semiconductor fabrication, where the neutral gas temperature (Tg) is one of the critical parameters influencing chemical reactions and plasma characteristics. Precise control of Tg significantly influences processes such as thin-film deposition and reactive ion etching, with its synergistic interaction with plasma parameters (ne, Te) often determining process outcomes. Consequently, a thorough understanding of the evolution of Tg and its correlation with discharge parameters has become a critical issue for optimizing semiconductor manufacturing processes. To achieve more accurate measurements of neutral gas temperature, this work employs three temperature measurement techniques: spectroscopy, Bragg grating, and fiber optic sensing. These methods are used to systematically investigate the variation patterns of neutral gas temperature (Tg) in nitrogen plasma and nitrogen-argon mixed plasma under different radio-frequency power, gas pressure, and gas composition conditions. To elucidate the gas heating mechanism, this work combines Langmuir probe measurements of electron density, electron temperature, electron energy probability distribution with a global model simulation. The results show that as the RF power increases, the energy coupled to the plasma increases, the ionization reaction is enhanced, and the collision process and energy transfer between electrons and neutral particles increase, resulting in a monotonically increasing trend of Tg. When gas pressure initially increases, both electron density and background gas density rise together, enhancing heating efficiency and driving rapid Tg growth. However, beyond 3 Pa, electron mean free path shortens and electron density declines. In contrast, background gas density continues to increase, leading to slower Tg growth. In nitrogen/argon mixed system discharges, increasing the argon proportion significantly enhances the rate of Tg increase. This occurs because a higher argon ratio elevates the proportion of high-energy electrons and electron density, thereby strengthening ionization and neutral gas heating. At the same time, argon metastable atoms enhance the density of excited nitrogen particles through the Penning process, which promotes nitrogen molecular excitation to higher energy levels and further heats the gas. Additionally, we observe that the radial temperature distribution in pure nitrogen plasma shifts from parabolic to saddle-type with axial height increasing, due to intensified electron collision excitation near the coil under electromagnetic field effects. In this study, it is also found that the glass transition temperature at the radial edge remains virtually unchanged as atmospheric pressure increases. This is because, as pressure continues to rise, electrons beneath the coil struggle to migrate to the radial edge to collide with neutral particles, thereby limiting the heating of edge neutral particles.
-
Keywords:
- neutral gas temperature /
- inductively coupled plasma /
- fiber optic sensing temperature measurement /
- radial distribution
-
图 1 ICP中性气体温度多手段测量实验装置
Figure 1. ICP neutral gas temperature multi-method measurement experimental apparatus.
图 2 气压为 1 Pa, 气体流量为50 mL/min (标准状况)时, 腔室中心处氮气中性气体温度随功率的变化 (a)光纤测温、布拉格光栅、发射光谱测量方法对比; (b)模拟结果
Figure 2. Temperature of nitrogen neutral gas at the center of the chamber as a function of power at a pressure of 1 Pa and gas flow rate of 50 mL/min (standard condition): (a) Comparison of three measurement methods of fiber optic temperature measurement, Bragg grating, and emission spectroscopy; (b) simulation results.
图 3 气压为1 Pa, 气体流量为50 mL/min (标准状况)时, 腔室中心处氮气电子密度和电子温度随功率的变化 (a), (c) 探针测量结果; (b), (d) 模拟结果
Figure 3. Nitrogen electron density and electron temperature at the center of the chamber as a function of power at a pressure of 1 Pa and gas flow rate of 50 mL/min (standard condition): (a), (c) Probe measurement results; (b), (d) simulation results.
图 4 气压为 1 Pa, 气体流量为50 mL/min (标准状况) 时, 纯氮气放电的EEPF随功率的变化
Figure 4. EEPF of pure nitrogen discharge as a function of power at a pressure of 1 Pa and gas flow rate of 50 mL/min (standard condition).
图 5 功率为600 W, 气体流量为50 mL/min (标准状况)时, 腔室中心处氮气中性气体温度随气压的变化 (a) 光纤测温、布拉格光栅、发射光谱测量方法对比; (b) 电子密度; (c) 电子温度; (d) EEPF
Figure 5. Temperature of nitrogen neutral gas at the center of the chamber as a function of pressure at a power of 600 W and gas flow rate of 50 mL/min (standard condition): (a) Comparison of measurement methods of fiber optic temperature measurement, Bragg grating, and emission spectroscopy; (b) electron density; (c) electron temperature; (d) EEPF.
图 6 功率为300 W, 气压为1 Pa, 气体流量为70 mL/min (标准状况)时, 腔室中心处氮气中性气体温度随氩含量的变化 (a) 光纤测温、布拉格光栅、发射光谱测量方法对比; (b) 电子密度; (c) 电子温度; (d) EEPF
Figure 6. Temperature of nitrogen neutral gas at the center of the chamber as a function of argon content at a power of 300 W, a pressure of 1 Pa, and gas flow rate of 70 mL/min (standard condition): (a) Comparison of measurement methods of fiber optic temperature measurement, Bragg grating, and emission spectroscopy; (b) electron density; (c) electron temperature; (d) EEPF.
图 7 固定气压为1 Pa、气体流量为50 mL/min (标准状况)时, 纯氮气放电中在不同高度不同功率下的Tg径向分布特征 (a) 30 mm; (b) 50 mm; (c) 70 mm; (d) 不同轴向高度、不同功率条件下的温度极差趋势图
Figure 7. Under fixed gas pressure of 1 Pa and gas flow rate of 50 mL/min (standard condition) the radial distribution characteristics of Tg during pure nitrogen discharge at different power levels at different height: (a) 30 mm; (b) 50 mm; (c) 70 mm; (d) temperature gradient trend diagram under varying axial heights and power conditions.
图 8 固定功率为 300 W、气体流量为50 mL/min(标准状况)时, 纯氮气放电中在不同高度不同气压下的 Tg径向分布特征 (a) 30 mm; (b) 50 mm; (c) 70 mm; (d) 不同轴向高度、不同功率条件下的温度极差趋势图
Figure 8. At a fixed power of 300 W and gas flow rate of 50 mL/min (standard condition), the radial distribution characteristics of Tg under different gas pressures during pure nitrogen discharge at different height: (a) 30 mm; (b) 50 mm; (c) 70 mm; (d) temperature gradient trend diagram under varying axial heights and power conditions.
表 1 模型中考虑的氮相关反应及系数
Table 1. Nitrogen-related reactions and coefficients considered in the model.
编号 反应表达式 反应系数/(cm3·s–1) 文献 1 $ \text{e}+{\text{N}}_{2}\rightarrow \text{N}_{2}^{+}+2\text{e} $ $ 7.76\times {10}^{-9}T_{\text{e}}^{0.79}\text{exp}(-16.75/{T}_{\text{e}}) $ [43] 2 $ \text{e}+\text{N}\rightarrow {\text{N}}^{+}+2\text{e} $ $ 3.87\times {10}^{-9}T_{\text{e}}^{0.86}\text{exp}(-14.62/{T}_{\text{e}}) $ [43] 3 $ \text{e}+{\text{N}}_{2}\rightarrow {\text{N}}^{+}+\text{N}+2\text{e} $ $ 2.90\times {10}^{-9}T_{\text{e}}^{0.72}\text{exp}(-29.71\text{/}{T}_{\text{e}}) $ [44] 4 $ \text{e}+{\text{N}}_{2}\rightarrow \text{N}+\text{N}+\text{e} $ $ 2.15\times {10}^{-8}\text{exp}(-14.39/{T}_{\text{e}}) $ [43] 5 $ \text{e}+{\text{N}}_{2}\rightarrow {\text{N}}_{2}\left(\text{A}\right)+\text{e} $ $ 8.06\times {10}^{-10}T_{\text{e}}^{-0.306}\text{exp}(-8.87/{T}_{\text{e}}) $ [43] 6 $ \text{e}+{\text{N}}_{2}\rightarrow {\text{N}}_{2}\left(\text{B}\right)+\text{e} $ $ 1.56\times {10}^{-8}T_{\text{e}}^{-0.52}\text{exp}(-9.16/{T}_{\text{e}}) $ [43] 7 $ \text{e}+{\text{N}}_{2}\rightarrow {\text{N}}_{2}\left({a}^{\prime} \right)+\text{e} $ $ 6.6\times {10}^{-9}T_{\text{e}}^{-0.66}\text{exp}(-11.05/{T}_{\text{e}}) $ [43] 8 $ \text{e}+\text{N}_{2}^{+}\rightarrow \text{N}+\text{N} $ $ 4.8\times {10}^{-7}\left(0.026/{T}_{\text{e}}\right) $ [45] 9 $ {\text{N}}_{2}\left(\text{A}\right)+{\text{N}}_{2}\left({a}^{\prime} \right)\rightarrow \text{N}_{2}^{+}+{\text{N}}_{2}+\text{e} $ $ 3.2\times {10}^{-12} $ [46] 10 $ {\text{N}}_{2}\left({a}^{\prime} \right)+{\text{N}}_{2}\left({a}^{\prime} \right)\rightarrow \text{N}_{2}^{+}+{\text{N}}_{2}+\text{e} $ $ 5.0\times {10}^{-11} $ [47] 11 $ {\text{N}}_{2}\left(\text{A}\right)+\text{N}\rightarrow {\text{N}}_{2}+\text{N} $ $ 2.0\times {10}^{-12} $ [44] 12 $ {\text{N}}_{2}\left(\text{A}\right)+{\text{N}}_{2}\rightarrow {\text{N}}_{2}+{\text{N}}_{2} $ $ 3.0\times {10}^{-18} $ [48] 13 $ {\text{N}}_{2}\left(\text{A}\right)+{\text{N}}_{2}\left(\text{A}\right)\rightarrow {\text{N}}_{2}\left(\text{B}\right)+{\text{N}}_{2} $ $ 7.7\times {10}^{-11} $ [47] 14 $ {\text{N}}_{2}\left(\text{B}\right)+{\text{N}}_{2}\rightarrow {\text{N}}_{2}+{\text{N}}_{2} $ $ 1.5\times {10}^{-12} $ [47] 15 $ {\text{N}}_{2}\left({a}^{\prime} \right)+{\text{N}}_{2}\rightarrow {\text{N}}_{2}\left(\text{B}\right)+{\text{N}}_{2} $ $ 1.9\times {10}^{-13} $ [49] 16 $ \text{N}+\text{N}+\text{N}\rightarrow {\text{N}}_{2}+\text{N} $ $ 1.0\times {10}^{-32} $(cm6·s–1) [50] 17 $ {\text{N}}_{2}\left(\text{B}\right)\rightarrow {\text{N}}_{2}\left(\text{A}\right)+\text{hν} $ $ 2.0\times {10}^{-5} $ [51] 注: 其中电子温度用电子伏(eV)为单位 
DownLoad: CSV
-
[1] Iliopoulos E, Adikimenakis A, Dimakis E, Tsagaraki K, Konstantinidis G, Georgakilas A 2005 J. Cryst. Growth 278 426
Google Scholar
[2] Osaka J, Senthil Kumar M, Toyoda H, Ishijima T, Sugai H, Mizutani T 2007 Appl. Phys. Lett. 90 172114
Google Scholar
[3] Kim K Y, Lee H C, Chung C W 2022 Plasma Sources Sci. Technol. 31 105007
Google Scholar
[4] Itagaki N, Iwata S, Muta K, Yonesu A, Kawakami S, Ishii N, Kawai Y 2003 Thin Solid Films 435 259
Google Scholar
[5] Agarwal S, Hoex B, van de Sanden M C M, Maroudas D, Aydil E S 2003 Appl. Phys. Lett. 83 4918
Google Scholar
[6] 高飞, 毛明, 丁振峰, 王友年 2008 物理学报 57 5123
Google Scholar
Gao F, Mao M, Ding Z F, Wang Y N 2008 Acta Phys. Sin. 57 5123
Google Scholar
[7] Hebner G A 1996 J. Appl. Phys. 80 2624
Google Scholar
[8] Bol’shakov A A, Cruden B A, Sharma S P 2004 Plasma Sources Sci. Technol. 13 691
Google Scholar
[9] 杨文斌, 周江宁, 李斌成, 邢廷文 2017 物理学报 66 095201
Google Scholar
Yang W B, Zhou J N, Li B C, Xing T W 2017 Acta Phys. Sin. 66 095201
Google Scholar
[10] 潘子峰, 陈仙辉, 王斌, 夏维东 2021 物理学报 70 085201
Google Scholar
Pan Z H, Chen X H, Wang C, Xia W D 2021 Acta Phys. Sin. 70 085201
Google Scholar
[11] Sing H, Coburn J W, Graves D B 2001 J. Vac. Sci. Technol. A 19 718
Google Scholar
[12] Wang Y J, Huang J W, Zhang Q Z, Zhang Y R, Gao F, Wang Y N 2021 Chin. Phys. B 30 095205 (in Chinese)
Google Scholar
[13] Donnelly V M, Malyshev M V 2000 Appl. Phys. Lett. 77 2467
Google Scholar
[14] Ostrikov K N, Denysenko I B, Tsakadze E L, Xu S, Storer R G 2002 J. Appl. Phys. 92 4935
Google Scholar
[15] Hash D B, Bose D, Rao M V V S, Cruden B A, Meyyappan M, Sharma S P 2001 J. Appl. Phys. 90 2148
Google Scholar
[16] Hebner G A, Miller P A 2000 J. Appl. Phys. 87 8304
Google Scholar
[17] Hebner G A 2001 J. Appl. Phys. 89 900
Google Scholar
[18] Sing H, Coburn J W, Graves D B 2001 J. Vac. Sci. Technol. A 19 718
Google Scholar
[19] Bol’shakov A A, Cruden B A, Sharma S P 2004 Plasma Sources Sci. Technol. 13 691.
Google Scholar
[20] Malyshev M V, Donnelly V M, Downey S W, Colonell J I, Layadi N 2000 J. Vac. Sci. Technol. A 18 849
Google Scholar
[21] Kiehlbauch M W, Graves D B 2001 J. Appl. Phys. 89 2047
Google Scholar
[22] Cruden B A, Rao M V V S, Sharma S P, Meyyappan M 2002 Appl. Phys. Lett. 81 990
Google Scholar
[23] Cruden B A, Rao M V V S, Sharma S P, Meyyappan M 2002 J. Appl. Phys. 91 8955
Google Scholar
[24] Schabel M J, Donnelly V M, Kornblit A, Tai W W 2002 J. Vac. Sci. Technol. A 20 555
Google Scholar
[25] Palmero A, Cotrino J, Barranco A, Gonzalez-Elipe A R 2002 Phys. Plasmas 9 358
Google Scholar
[26] Britun N, Gaillard M, Ricard A, Kim Y M, Kim K S, Han J G 2007 J. Phys. D: Appl. Phys. 40 1022
Google Scholar
[27] Han J, Park W, Kim J, Lim K H, Lee G H, In S, Park J, Oh S J, Nam S K, Sung D Y, Moon S Y 2023 Spectrochim. Acta A 302 123389
[28] Du P C, Zhou F J, Zhao K 2022 Appl. Phys. 132 043302
Google Scholar
[29] Zhang L 2021 Ph. D. Dissertation (Dalian: Dalian University of Technology
[30] Lv T 2023 Ph. D. Dissertation (Dalian: Dalian University of Technology
[31] 佟磊, 赵明亮, 张钰如, 宋远红, 王友年 2024 物理学报 73 045201
Google Scholar
Tong L, Zhao M L, Zhang Y R, Song Y H, Wang Y N 2024 Acta Phys. Sin. 73 045201
Google Scholar
[32] Wen D Q 2018 Ph. D. Dissertation (Dalian: Dalian University of Technology
[33] Gudmundsson J T, Kouznetsov I G, Patel K K, Lieberman M A 2001 J. Phys. D: Appl. Phys. 34 1100
Google Scholar
[34] Gudmundsson J T, Thorsteinsson E G 2007 Plasma Sources Sci. Technol. 16 399
Google Scholar
[35] Bakowski B, Hancock G, Peverall R, Ritchie G A D, Thornton L J 2004 J. Phys. D: Appl. Phys. 37 2064
Google Scholar
[36] Tuszewski M 2006 J. Appl. Phys. 100 05330
[37] Shimada M, Tynan G R, Cattolica R 2006 J. Vac. Sci. Technol. A 24 1878
Google Scholar
[38] Britun N, Gaillard M, Ricard A, Kim Y M, Kim K S, Han J G 2007 J. Phys. D: Appl. Phys. 40 1022
Google Scholar
[39] Bol’shakov A A, Cruden B A, Sharma S P 2004 Plasma Sources Sci. Technol. 13 691
Google Scholar
[40] Biloiu C, Sun X, Harvey Z, Scime E 2007 J. Appl. Phys. 101 073303
Google Scholar
[41] Linss V, Kupfer H, Peter S, Richter F 2005 Surf. Coat. Technol. 200 1696
Google Scholar
[42] Thorsteinsson E G, Gudmundsson J T 2009 Plasma Sources Sci. Technol. 18 045001
Google Scholar
[43] Gudmundsson J T 2005 Report No. RH-09-2005 (University of Iceland
[44] Sode M, Jacob W, Schwarz-Selinger T, Kersten H 2015 J. Appl. Phys. 117 083303
[45] Levaton J, Amorim J, Souza A R, Franco D, Ricard A 2002 J. Phys. D: Appl. Phys. 35 689
Google Scholar
[46] Loureiro J 1997 J. Phys. D: Appl. Phys. 30 2320
Google Scholar
[47] Guerra V, Loureiro J M A H 1997 Plasma Sources Sci. Technol. 6 361
Google Scholar
[48] Pejovic M M, Zivanovic E N, Pejovic M M 2004 J. Phys. D: Appl. Phys. 37 200
Google Scholar
[49] Piper L G 1987 J. Chem. Phys. 87 1625
[50] Gordiets B F, Ferreira C M, Guerra V L, Loureiro J M A H, Nahorny J, Pagnon D, Touzeau M, Vialle M 1995 IEEE Trans. Plasma Sci. 23 750
Google Scholar
[51] Piper L G 1989 J. Chem. Phys. 91 864
Google Scholar
[52] Kossyi I A, Kostinsky A Y, Matveyev A A, Silakov V P 1992 Plasma Sources Sci. Technol. 1 207
Google Scholar
[53] Kim K Y, Kim J H, Chung C W, Lee H C 2022 Plasma Sources Sci. Technol. 31 105007
Google Scholar
[54] Song M A, Lee Y W, Chung T H 2011 Phys. Plasmas 18 023504
Google Scholar
[55] Luo Q, Lv T, Wang P Y, Zhou D P, Gao F, Wang Y N 2025 J. Vac. Sci. Technol. A 43 043006
Google Scholar
DownLoad:
Metrics
- Abstract views: 517
- PDF Downloads: 13
- Cited By: 0
