隧穿磁阻传感器研究进展

周子童; 闫韶华; 赵巍胜; 冷群文

doi:10.7498/aps.71.20211883

隧穿磁阻传感器研究进展

1.
北京航空航天大学集成电路科学与工程学院, 北京　100191
2.
北京航空航天大学青岛研究院, 北航歌尔微电子研究院, 青岛　266000

通讯作者: E-mail: weisheng.zhao@buaa.edu.cn; E-mail: lengqw@bhqditi.com

中图分类号: 85.75.Ss, 73.43.Qt, 75.47.Gk, 85.70.-w

Research progress of tunneling magnetoresistance sensor

1.
School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
2.
Institute of Beihang-Goertek Microelectronics, Qingdao Research Institute, Beihang University, Qingdao 266000, China

Corresponding authors: E-mail: weisheng.zhao@buaa.edu.cn; E-mail: qunwen.leng@goertekusa.com

MSC: 85.75.Ss, 73.43.Qt, 75.47.Gk, 85.70.-w

摘要: 传感器作为物联网技术的基石, 在人们的生产生活中发挥着重大作用. 其中, 基于隧穿磁阻效应(tunneling magnetoresistance, TMR)的磁传感器具有灵敏度高、尺寸小、功耗低等优点, 在导航定位、生物医学、电流检测和无损检测等领域具有极大的应用前景. 本综述以TMR传感器技术路线的发展为核心, 囊括了从基本传感单元到三维空间磁场检测, 再到实际应用的多个研究重点. 首先, 介绍了TMR传感器发展历程并阐明其基本工作原理, 讨论了提高单个传感单元磁隧道结输出线性度的方法. 接下来, 详细介绍了传感器的重要电路结构—惠斯通电桥, 以及制备TMR全桥结构的多种工艺方法. 进一步, 从三维空间磁场检测这一市场需求入手, 深入讨论了基于TMR传感器的三维传感结构的设计和制备方法. 同时, 以传感器灵敏度和噪声水平这两大基本性能为切入点, 列举了TMR传感器性能的优化方案. 最后, 本文对TMR传感器的应用展开了详细介绍, 以自旋麦克风, 生物传感器两个新兴应用为例, 对TMR传感器未来在物联网中的发展和应用进行了展望.
- 隧穿磁阻传感器 /
- 线性化方法 /
- 磁传感器噪声 /
- 智能应用
Abstract: Sensors play an important role in Internet of Things (IoT) industry and account for a rapidly growing market share. Among them, the magnetic sensor based on tunneling magnetoresistance (TMR) effect possesses great potential applications in the fields of biomedical, navigation, positioning, current detection, and non-destructive testing due to its extremely high sensitivity, small device size and low power consumption. In this paper, we focus on the development of TMR sensor technology routes, covering a series of research advances from a sensor transducer to three-dimensional magnetic field detection, and then to the applications. Firstly, we recall the development history of TMR sensors, explain its working principle, and discuss the method to improve the output linearity of single magnetic tunnel junction. Next, we state the Wheatstone-bridge structure, which can inhibit temperature drift in detail and review several methods of fabricating the full bridge of TMR sensors. Furthermore, for the market demand of three-dimensional magnetic field detection, we summarize the methods of designing and fabricating three-dimensional sensing structure of the TMR sensor. At the same time, we list several optimization schemes of TMR sensor performance in terms of sensitivity and noise level. Finally, we discuss two types of emerging applications of TMR sensors in recent years. The TMR sensors can also be used in intelligence healthcare due to their ultra-high sensitivity. In addition, devices from the combination of spin materials and MEMS structure have attracted wide attention, especially, because of the large commercial market of microphones, spin-MEMS microphones utilized TMR techniques will be the next research hotspot in this interdisciplinary field.
- tunneling magnetoresistance sensors /
- linearization methods /
- sensor noise /
- intelligent applications .

图 1 磁隧道结　(a) 膜层示意图; (b) R-H曲线图

Figure 1. Magnetic tunnel junction: (a) Schematic diagram of the MTJ stacks; (b) R-H loop curve.

下载: 全尺寸图片幻灯片

图 2 TMR传感器的图形化工艺流程图

Figure 2. Flow chart of pattern process of TMR sensors.

下载: 全尺寸图片幻灯片

图 3 线性化方案图示　(a) 外加偏置场结构; (b) 强形状各向异性结构; (c) 双钉扎结构; (d) 交叉易磁化轴结构

Figure 3. Linearization scheme diagram: (a) MTJ junction with bias field; (b) MTJ junction with strong shape anisotropic; (c) MTJ junction of double pinning; (d) MTJ junction with linear perpendicular magnetic anisotropy.

下载: 全尺寸图片幻灯片

图 4 惠斯通电桥结构示意图

Figure 4. Schematic diagram of the Wheatstone-bridge structure

下载: 全尺寸图片幻灯片

图 5 惠斯通全桥制备方法　(a) 机械组装式; (b) 局部退火式; (c) 分区域光刻式; (d) 后退火式

Figure 5. Wheatstone bridge manufacturing method: (a) Mechanical assembly; (b) local annealing; (c) divide different areas for photolithography; (d) annealing after pattern process.

下载: 全尺寸图片幻灯片

图 6 组装式三维TMR传感器　(a)传感器结构示意图; (b)带软磁管降噪的三维结构^[38]

Figure 6. Assembled three-dimensional TMR sensor: (a) Schematic diagram of sensor structure; (b) three-dimensional structure with soft magnetic tube for noise reduction^[38].

下载: 全尺寸图片幻灯片

图 7 带磁通控制器的三维磁阻式传感器　(a) 传感器结构示意图^[42]; (b) 磁通控制器对于Z轴磁场磁通量的影响^[43]

Figure 7. Three-dimensional TMR sensor with flux guides: (a) Schematic diagram of sensor structure^[42]; (b) effect of flux guides on magnetic flux of Z-axis magnetic field^[43].

下载: 全尺寸图片幻灯片

图 8 传感器后端基本电路结构图

Figure 8. Basic back-end circuit diagram of sensor.

下载: 全尺寸图片幻灯片

图 9 磁通聚集器的结构图以及周围磁通量分布情况^[52]　(a) 光学显微镜下磁通聚集器和磁隧道结; (b) 磁通聚集器两端的模拟磁通量浓度; (c) 模拟磁通量浓度区域放大图

Figure 9. The structure diagram of the magnetic flux concentrator and the surrounding magnetic flux distribution^[52]: (a) Magnetic flux concentrator and magnetic tunnel junction under light microscope; (b) simulated magnetic flux concentrations at both ends of the flux concentrator; (c) enlarged image of simulated magnetic flux concentration area.

下载: 全尺寸图片幻灯片

图 10 噪声功率谱密度曲线　(a) 热噪声和1/f噪声功率谱密度曲线; (b) RTN噪声功率谱密度曲线^[69]

Figure 10. Noise power spectral density curve: (a) Power spectral density curves of thermal noise and 1/ f noise; (b) RTN noise power spectral density curve^[69].

下载: 全尺寸图片幻灯片

图 11 通过串并联MTJ来降低噪声的方法

Figure 11. Noise is reduced by series and parallel MTJ.

下载: 全尺寸图片幻灯片

图 12 水平运动磁通聚集器原理图^[81]

Figure 12. Schematic diagram of horizontal motion flux concentrator^[81].

下载: 全尺寸图片幻灯片

图 13 垂直运动磁通聚集器原理图^[83]　(a) 磁通调制膜靠近间隙; (b) 远离间隙

Figure 13. Schematic diagram of vertical motion flux concentrator^[83]: (a) The state of flux modulated film close to the air gap; (b) the state of flux modulated film far away from the air gap.

下载: 全尺寸图片幻灯片

图 14 电调制磁通聚集器原理图^[89]　(a) 电调制磁通聚集器结构图; (b) 电压为0时的磁通分布; (c) 电压为V_i时的磁通分布; (d) 磁通调制膜的磁导率和空气间隙中的磁通量随着电压发生周期性变化

Figure 14. Schematic diagram of magnetic flux electric modulation^[89]: (a) Structure diagram of MFEM; (b) the magnetic flux distribution at voltage = 0; (c) the magnetic flux distribution at voltage = V_i; (d) the permeability of the FXF and the magnetic flux in the air gap change periodically with the voltage.

下载: 全尺寸图片幻灯片

图 15 自旋-MEMS麦克风^[106]　(a) 原理图; (b) 版图结构

Figure 15. Spin-MEMS microphone^[106]: (a) Schematic diagram; (b) physical structure.

下载: 全尺寸图片幻灯片

图 16 集成TMR传感器的可穿戴眼动仪工作原理^[109]

Figure 16. Working principle diagram of wearable eye tracker integrated with TMR sensor^[109].

下载: 全尺寸图片幻灯片

图 17 TMR传感器在心磁图和脑磁图测试中的应用^[110]　(a) 心磁场测试原理图; (b) 脑磁场测试原理图

Figure 17. Application of TMR sensor in magnetocardiogram and magnetoencephalography testing^[110]: (a) Schematic diagram of magnetocardiogram testing; (b) schematic diagram of magnetoencephalography testing.

下载: 全尺寸图片幻灯片

表 1 不同磁传感器技术性能对比^[14]

Table 1. Performance comparison of different magnetic sensor technologies^[14].

	HALL	AMR	GMR	TMR
物理效应	霍尔效应	各向异性磁阻效应	巨磁阻效应	隧穿磁阻效应
感应方向	垂直	面内	面内	面内/垂直
最大磁阻率/%	—	2.0^[23]	24^[24]	604^[10,11]
磁场探测范围/T	10^–3—10	10^–9—10^–3	10^–5—10⁴	10^–12—10
退火温度/℃	—	—	220—280	280—340
磁场灵敏度/(mV·V^–¹·Oe^–1)	~0.05	~1	~3	~100
噪声指数/(nT·Hz^–1/2)@1 Hz	>100	0.1—10	1—10	0.01~10
功耗/mA	5—10	1—10	1—10	0.001—0.1
芯片尺寸/mm²	~1×1	~1×1	~0.5×0.5	~0.5×0.5

下载: 导出CSV

[1]	Liu X, Lam K H, Zhu K, Zheng C, Li X, Du Y, Liu C, Pong P W T 2019 IEEE Trans. Magn. 55 1 doi: 10.1109/TMAG.2019.2927457
[2]	Mohsen A, Al-Mahdawi M, Fouda M M, Oogane M, Ando Y, Fadlullah Z M 2020 ICC 2020-2020 IEEE International Conference on Communications (ICC) Dublin Ireland, 27 July 2020 pp1–6
[3]	Leroy P, Coillot C, Mosser V, Roux A, Chanteur G 2007 Sens. Lett. 5 162 doi: 10.1166/sl.2007.049
[4]	Thomson W 1857 Proc. R. Soc. London 8 546
[5]	Baibich M N, Broto J M, Fert A, Van Dau F N, Petroff F, Etienne P, Creuzet G, Friederich A, Chazelas J 1988 Phys. Rev. Lett. 61 2472 doi: 10.1103/PhysRevLett.61.2472
[6]	Binasch G, Grünberg P, Saurenbach F, Zinn W 1989 Phys. Rev. B 39 4828
[7]	Julliere M 1975 Phys. Lett. A 54 225 doi: 10.1016/0375-9601(75)90174-7
[8]	Miyazaki T, Tezuka N 1995 J. Magn. Magn. Mater. 139 L231 doi: 10.1016/0304-8853(95)90001-2
[9]	Moodera J S, Kinder L R, Wong T M, Meservey R 1995 Phys. Rev. Lett. 74 3273 doi: 10.1103/PhysRevLett.74.3273
[10]	Parkin S S, Kaiser C, Panchula A, Rice P M, Hughes B, Samant M, Yang S H 2004 Nat. Mater. 3 862 doi: 10.1038/nmat1256
[11]	Ikeda S, Hayakawa J, Ashizawa Y, Lee Y, Miura K, Hasegawa H, Tsunoda M, Matsukura F, Ohno H 2008 Appl. Phys. Lett. 93 082508 doi: 10.1063/1.2976435
[12]	Cao Z, Chen W, Lu S, Yan S, Zhang Y, Zhou Z, Yang Y, Li Z, Zhao W, Leng Q 2021 Appl. Phys. Lett. 118 122402 doi: 10.1063/5.0041170
[13]	Chen W, Yan S, Yang Y, Cao Z, Lin Y, Zhou Z, Yan S, Leng Q 2021 2021 5th IEEE Electron Devices Technology & Manufacturing Conference (EDTM) Chengdu China, 8–11 April 2021 pp1–3
[14]	Tumanski S 2016 Handbook of Magnetic Measurements (CRC Press) pp159–256
[15]	Su D, Wu K, Saha R, Peng C, Wang J P 2020 Micromachines 11 34
[16]	Wang M, Wang Y, Peng L, Ye C 2019 IEEE Sens. J. 19 9610 doi: 10.1109/JSEN.2019.2927086
[17]	Ichkitidze L, Bazaev N, Telyshev D, Preobrazhensky R, Gavrushina M 2015 Biomed. Eng. 48 305 doi: 10.1007/s10527-015-9475-0
[18]	Markevicius V, Navikas D, Zilys M, Andriukaitis D, Valinevicius A, Cepenas M 2016 Sensors 16 78 doi: 10.3390/s16010078
[19]	Zhou X 2013 2013 IEEE Sensors Applications Symposium Proceedings Galveston TX USA, 19–21 February 2013 pp80–83
[20]	Rosado L S, Cardoso F A, Cardoso S, Ramos P M, Freitas P P, Piedade M S 2014 Sens. Actuators, A 212 58 doi: 10.1016/j.sna.2014.03.021
[21]	Sun X, Huang Q, Hou Y, Jiang L, Pong P W 2013 IEEE Trans. Power Delivery 28 2145 doi: 10.1109/TPWRD.2013.2264102
[22]	Jin Z, Mohd Noor Sam M A I, Oogane M, Ando Y 2021 Sensors 21 668 doi: 10.3390/s21020668
[23]	Wang C, Su W, Hu Z, Pu J, Guan M, Peng B, Li L, Ren W, Zhou Z, Jiang Z 2018 IEEE Trans. Magn. 54 1 doi: 10.1109/TMAG.2018.2846758
[24]	Diao Z, Zheng Y, Kaiser C, Jiang X, Chen L, Roy A, Chien C, Wang M, Gider S, Mauri D 2015 2015 IEEE International Magnetics Conference (INTERMAG) Beijing China, 11–15 May 2015 p1
[25]	Liu X, Ren C, Xiao G 2002 J. Appl. Phys. 92 4722 doi: 10.1063/1.1507818
[26]	Chaves R, Cardoso S, Ferreira R, Freitas P 2011 J. Appl. Phys. 109 07E506 doi: 10.1063/1.3537926
[27]	Silva A V, Leitao D C, Valadeiro J, Amaral J, Freitas P P, Cardoso S 2015 Eur. Phys. J. :Appl. Phys. 72 10601 doi: 10.1051/epjap/2015150214
[28]	Wiśniowski P, Almeida J, Cardoso S, Barradas N, Freitas P 2008 J. Appl. Phys. 103 07A910 doi: 10.1063/1.2838626
[29]	Van Driel J, De Boer F, Lenssen K M, Coehoorn R 2000 J. Appl. Phys. 88 975 doi: 10.1063/1.373764
[30]	van Dijken S, Coey J 2005 Appl. Phys. Lett. 87 022504 doi: 10.1063/1.1957111
[31]	Wei H, Qin Q, Wen Z, Han X, Zhang XG 2009 Appl. Phys. Lett. 94 172902 doi: 10.1063/1.3126064
[32]	Nakano T, Oogane M, Furuichi T, Ando Y 2017 Appl. Phys. Lett. 110 012401 doi: 10.1063/1.4973462
[33]	Yuan L, Liou SH, Wang D 2006 Phys. Rev. B 73 134403 doi: 10.1103/PhysRevB.73.134403
[34]	Reig C, Cardoso S, Mukhopadhyay S C 2013 Smart Sensors, Measurement and Instrumentation (Springer) pp103–131
[35]	Cao J, Freitas P 2010 J. Appl. Phys. 107 09E712 doi: 10.1063/1.3360583
[36]	Berthold I, Müller M, Klötzer S, Ebert R, Thomas S, Matthes P, Albrecht M, Exner H 2014 Appl. Surf. Sci. 302 159 doi: 10.1016/j.apsusc.2014.02.133
[37]	Franco F, Silva M, Cardoso S, Freitas P P 2021 Appl. Phys. Lett. 118 072401 doi: 10.1063/5.0035048
[38]	Luong V, Jeng J, Lai B, Lu C 2015 2015 IEEE International Magnetics Conference (INTERMAG) Beijing China, 11–15 May 2015 p1
[39]	Freitas P P, Ferreira R, Cardoso S 2016 Proc. IEEE 104 1894 doi: 10.1109/JPROC.2016.2578303
[40]	Yan S, Cao Z, Guo Z, Zheng Z, Cao A, Qi Y, Leng Q, Zhao W 2018 Sensors 18 1832 doi: 10.3390/s18061832
[41]	Cao Z, Wei Y, Chen W, Yan S, Lin L, Li Z, Wang L, Yang H, Leng Q, Zhao W 2021 Sci. China: Inf. Sci. 64 1
[42]	Luong V S, Jeng J T, Lai B L, Hsu J H, Chang C R, Lu C C 2015 IEEE Trans. Magn. 51 4004504 doi: 10.1109/TMAG.2015.2443024
[43]	Lu C C, Huang J 2015 Sensors 15 14727 doi: 10.3390/s150614727
[44]	Cerro G, Ferrigno L, Laracca M, Milano F, Bellitti P, Serpelloni M, Piedrafita O C 2020 2020 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Dubrovnik Croatia, 25–28 May 2020 pp1–6
[45]	Deak Z J 2015 Association for Sensors and Measurement (AMA) Conferences Nürnberg Germany, 19–21 May 2015 pp245–250
[46]	Chiang C Y, Jeng J T, Lai B L, Luong V S, Lu C C 2015 J. Appl. Phys. 117 17A321 doi: 10.1063/1.4916036
[47]	Su Y H, Lu C C, Jeng J T, Hsu J H, Liao M H, Wu J C, Lai M H, Chang C R 2017 IEEE Trans. Nanotechnol. 17 11 doi: 10.1109/TNANO.2017.2660062
[48]	Yan S, Zhou Z, Cao Z, Yang Y, Li Z, Chen W, Leng Q, Zhao W 2021 2021 5th IEEE Electron Devices Technology & Manufacturing Conference (EDTM) Chengdu China, 8–11 April 2021 pp1–3
[49]	Li R, Zhang S, Luo S, Guo Z, Xu Y, Ouyang J, Song M, Zou Q, Xi L, Yang X 2021 Nat. Electron. 4 179 doi: 10.1038/s41928-021-00542-8
[50]	TDK 2020 TDK Product Catalog [EB/OL]
[51]	Lee Y, Hayakawa J, Ikeda S, Matsukura F, Ohno H 2007 Appl. Phys. Lett. 90 212507 doi: 10.1063/1.2742576
[52]	Almeida J, Freitas P 2009 J. Appl. Phys. 105 07E722 doi: 10.1063/1.3077228
[53]	Orgassa D, Fujiwara H, Schulthess T, Butler W 1999 Phys. Rev. B 60 13237 doi: 10.1103/PhysRevB.60.13237
[54]	Tezuka N, Ikeda N, Mitsuhashi F, Sugimoto S 2009 Appl. Phys. Lett. 94 162504 doi: 10.1063/1.3116717
[55]	Fujiwara K, Oogane M, Yokota S, Nishikawa T, Naganuma H, Ando Y 2012 J. Appl. Phys. 111 07C710 doi: 10.1063/1.3677266
[56]	Lei Z, Li G, Egelhoff W F, Lai P, Pong P W 2011 IEEE Trans. Magn. 47 602 doi: 10.1109/TMAG.2010.2100814
[57]	Nyquist H 1928 Phys. Rev. 32 110 doi: 10.1103/PhysRev.32.110
[58]	Johnson J B 1928 Phys. Rev. 32 97 doi: 10.1103/PhysRev.32.97
[59]	Ingvarsson S, Xiao G, Parkin S, Gallagher W, Grinstein G, Koch R 2000 Phys. Rev. Lett. 85 3289 doi: 10.1103/PhysRevLett.85.3289
[60]	Smith N, Arnett P 2001 Appl. Phys. Lett. 78 1448 doi: 10.1063/1.1352694
[61]	Egelhoff Jr W, Pong P, Unguris J, McMichael R, Nowak E, Edelstein A, Burnette J, Fischer G 2009 Sens. Actuators, A 155 217 doi: 10.1016/j.sna.2009.08.016
[62]	Freitas P, Ferreira R, Cardoso S, Cardoso F 2007 J. Phys.: Condens. Matter 19 165221 doi: 10.1088/0953-8984/19/16/165221
[63]	Nowak E, Weissman M, Parkin S 1999 Appl. Phys. Lett. 74 600 doi: 10.1063/1.123158
[64]	Almeida J, Wisniowski P, Freitas P 2008 IEEE Trans. Magn. 44 2569 doi: 10.1109/TMAG.2008.2002604
[65]	Liou S H, Zhang R, Russek S E, Yuan L, Halloran S T, Pappas D P 2008 J. Appl. Phys. 103 07E920 doi: 10.1063/1.2837659
[66]	Kandiah K, Whiting F 1978 Solid·State Electron. 21 1079
[67]	Xi H, Loven J, Netzer R, Guzman J I, Franzen S, Mao S 2006 J. Phys. D: Appl. Phys. 39 2024 doi: 10.1088/0022-3727/39/10/007
[68]	Polovy H, Guerrero R, Scola J, Pannetier-Lecoeur M, Fermon C, Feng G, Fahy K, Cardoso S, Almeida J, Freitas P 2010 J. Magn. Magn. Mater. 322 1624 doi: 10.1016/j.jmmm.2009.05.060
[69]	Torrejon J, Solignac A, Chopin C, Moulin J, Doll A, Paul E, Fermon C, Pannetier-Lecoeur M 2020 Phys. Rev. Appl. 13 034031 doi: 10.1103/PhysRevApplied.13.034031
[70]	Garzon S, Chen Y, Webb R A 2007 Physica E (Amsterdam, Neth. ) 40 133
[71]	Fermon C, Pannetier-Lecoeur M 2013 Giant Magnetoresistance (GMR) Sensors (Springer) pp47–70
[72]	Wisniowski P, Almeida J M, Freitas P P 2008 IEEE Trans. Magn. 44 2551 doi: 10.1109/TMAG.2008.2003067
[73]	Deak J G, Zhou Z, Shen W 2017 AIP Adv. 7 056676 doi: 10.1063/1.4978465
[74]	Moulin J, Doll A, Paul E, Pannetier-Lecoeur M, Fermon C, Sergeeva-Chollet N, Solignac A 2019 Appl. Phys. Lett. 115 122406 doi: 10.1063/1.5108604
[75]	Huang L, Yuan Z, Tao B, Wan C, Guo P, Zhang Q, Yin L, Feng J, Nakano T, Naganuma H 2017 J. Appl. Phys. 122 113903 doi: 10.1063/1.4990478
[76]	Cui Y, Khodadadi B, Schäfer S, Mewes T, Lu J, Wolf S A 2013 Appl. Phys. Lett. 102 162403 doi: 10.1063/1.4802952
[77]	Valadeiro J P, Amaral J, Leitao D C, Ferreira R, Cardoso S F, Freitas P J 2015 IEEE Trans. Magn. 51 4400204 doi: 10.1109/TMAG.2014.2352115
[78]	Tondra M, Daughton J M, Wang D, Beech R S, Fink A, Taylor J A 1998 J. Appl. Phys. 83 6688 doi: 10.1063/1.367861
[79]	Guerrero R, Pannetier-Lecoeur M, Fermon C, Cardoso S, Ferreira R, Freitas P 2009 J. Appl. Phys. 105 113922 doi: 10.1063/1.3139284
[80]	Edelstein A S, Fischer G A 2002 J. Appl. Phys. 91 7795 doi: 10.1063/1.1451901
[81]	Edelstein A, Fischer G, Pedersen M, Nowak E, Cheng S F, Nordman C 2006 J. Appl. Phys. 99 08B317 doi: 10.1063/1.2170067
[82]	Guedes A, Jaramillo G, Buffa C, Vigevani G, Cardoso S, Leitao D, Freitas P, Horsley D 2012 IEEE Trans. Magn. 48 4115 doi: 10.1109/TMAG.2012.2203297
[83]	Hu J, Pan M, Tian W, Chen D, Zhao J, Luo F 2012 Appl. Phys. Lett. 100 244102 doi: 10.1063/1.4729427
[84]	Hu J, Pan M, Tian W, Chen D, Zhao J 2012 Rev. Sci. Instrum. 83 055009 doi: 10.1063/1.4723823
[85]	Du Q, Hu J, Sun K, Chen D, Pan L, Che Y, Zhang X, Li P, Zhang B, Peng J 2019 IEEE Electron Device Lett. 40 1824 doi: 10.1109/LED.2019.2944645
[86]	Hu J, Du Q, Pan M, Li P, Sun K, Wang W, Zhang J, Peng J, Qiu W, Chen D 2020 2020 IEEE Sensors Rotterdam Netherlands, October 25–28, 2020 pp1–4
[87]	Zhang J, Pan M, Du Q, Hu J, Sun K, Yu Y, Zhang X, Luo H 2021 Micromachines 12 722 doi: 10.3390/mi12060722
[88]	Liu Z, Chen J, Zou X 2021 Sensors 21 87
[89]	Pan L, Pan M, Hu J, Hu Y, Che Y, Yu Y, Wang N, Qiu W, Li P, Peng J 2020 Sensors 20 1440 doi: 10.3390/s20051440
[90]	Che Y, Hu J, Pan L, Li P, Pan M, Chen D, Sun K, Zhang X, Du Q, Yu Y 2020 AIP Adv. 10 105032 doi: 10.1063/5.0023826
[91]	Zheng C, Zhu K, De Freitas S C, Chang J Y, Davies J E, Eames P, Freitas P P, Kazakova O, Kim C, Leung C W 2019 IEEE Trans. Magn. 55 0800130 doi: 10.1109/TMAG.2019.2896036
[92]	Song D, Nowak J, Larson R, Kolbo P, Chellew R 2000 IEEE Trans. Magn. 36 2545 doi: 10.1109/20.908503
[93]	Vopsaroiu M, Blackburn J, Cain M G 2007 J. Phys. D:Appl. Phys. 40 5027 doi: 10.1088/0022-3727/40/17/003
[94]	Hayakawa J, Ikeda S, Lee Y M, Sasaki R, Meguro T, Matsukura F, Takahashi H, Ohno H 2005 Jpn. J. Appl. Phys. 44 L1267 doi: 10.1143/JJAP.44.L1267
[95]	Diao Z, Apalkov D, Pakala M, Ding Y, Panchula A, Huai Y 2005 Appl. Phys. Lett. 87 232502 doi: 10.1063/1.2139849
[96]	Aurelio D, Torres L, Finocchio G 2009 J. Magn. Magn. Mater. 321 3913 doi: 10.1016/j.jmmm.2009.07.050
[97]	Jeng J T, Lu C C, Hsu H Y 2017 Measurement 109 297 doi: 10.1016/j.measurement.2017.05.062
[98]	Deak J, Jin I 2019 IEEE Trans. Magn. 55 6700104 doi: 10.1109/TMAG.2018.2850748
[99]	Hainz S, de la Torre E, Guettinger J 2021 AmE 2021-Automotive Meets Electronics; 12th GMM-Symposium online, March 10–11, 2021 pp1–4
[100]	Rohrmann K, Sandner M, Meier P, Prochaska M 2018 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Houston TX USA, May 14–17, 2018 pp1–6
[101]	Guo D, Cardoso F, Ferreira R, Paz E, Cardoso S, Freitas P 2014 J. Appl. Phys. 115 17E513 doi: 10.1063/1.4863933
[102]	Lawrence D, Donnal J S, Leeb S 2016 IEEE Sens. J. 16 6095 doi: 10.1109/JSEN.2016.2574245
[103]	Simmons L P, Welsh J S 2013 5th International Conference on Computational Intelligence, Modelling and Simulation Seoul Korea (South), September 24–25, 2013 pp69–74
[104]	Sedaghat S B, Ganji B A 2019 Microsyst. Technol. 25 217 doi: 10.1007/s00542-018-3951-x
[105]	Fuji Y, Hara M, Higashi Y, Kaji S, Masunishi K, Nagata T, Yuzawa A, Otsu K, Okamoto K, Baba S 2017 19th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS) Kaohsiung Taiwan, June 18–22, 2017 pp63–66
[106]	Higashi Y, Fuji Y, Kaji S, Masunishi K, Nagata T, Yuzawa A, Otsu K, Okamoto K, Baba S, Ono T 2018 IEEE Micro Electro Mechanical Systems (MEMS) Belfast UK, January 21–25, 2018 pp1060–1063
[107]	Fuji Y, Higashi Y, Kaji S, Masunishi K, Yuzawa A, Nagata T, Okamoto K, Baba S, Ono T, Hara M 2018 IEEE International Electron Devices Meeting (IEDM) San Francisco CA USA, December 1–5, 2018 pp4.2.1–4.2. 4
[108]	Bermúdez G S C, Fuchs H, Bischoff L, Fassbender J r, Makarov D 2018 Nat. Electron. 1 589 doi: 10.1038/s41928-018-0161-6
[109]	Tanwear A, Liang X, Liu Y, Vuckovic A, Ghannam R, Böhnert T, Paz E, Freitas P P, Ferreira R, Heidari H 2020 IEEE Trans. Biomed. Circuits Syst. 14 1299 doi: 10.1109/TBCAS.2020.3027242
[110]	Fujiwara K, Oogane M, Kanno A, Imada M, Jono J, Terauchi T, Okuno T, Aritomi Y, Morikawa M, Tsuchida M 2018 Appl. Phys. Express 11 023001 doi: 10.7567/APEX.11.023001
[111]	Hajba L, Guttman A 2016 Biotechnol. Adv. 34 354 doi: 10.1016/j.biotechadv.2016.02.001
[112]	Liu W J, Ou S L, Chang Y H, Chen Y T, Liang Y C, Chang C Y, Chu C L, Wu T H 2021 Surf. Eng. 37 429 doi: 10.1080/02670844.2020.1753398
[113]	Kim K, Hall D A, Yao C, Lee J R, Ooi C C, Bechstein D J, Guo Y, Wang S X 2018 Sci. Rep. 8 1

图( 17) 表( 1)

计量

文章访问数: 1110
HTML全文浏览数: 1110
PDF下载数: 15
施引文献: 0

全文HTML

1. 引　言

近年来, 受物联网(internet of things, IoT)产业驱动, 传感器迎来了飞速发展. 传感器种类繁多, 从不同类型的应用场景中收集数据, 提高生产生活效率, 为万物互联赋能. 其中, 磁传感器占据了物联网各类智能传感器约10%的份额^[1,2], 从检测地磁场用于导航交通, 到检测神经元活动产生的极微弱磁场用于医疗诊断, 磁传感器的应用无处不在.

随着人们对传感器高灵敏度、低功耗、小型化等性能需求的提高, 集成电路中微型磁传感器所使用的技术也在不断更新, 目前主要包括霍尔效应(Hall effect)、各向异性磁阻(anisotropic magnetoresistance, AMR)效应、巨磁阻(giant magnetoresistance, GMR)效应以及隧穿磁阻(tunneling magnetoresistance, TMR)效应四种. 其中, 霍尔传感器是发展最为成熟的商业产品, 原理简单, 制备成本低, 但是霍尔传感器需要集成聚磁环结构来提高灵敏度^[3], 器件尺寸较大, 同时霍尔元件又有功耗高, 线性度差等缺点. 因此, 基于磁阻效应的磁传感器得益于其低功耗、高灵敏度、易集成等优点, 开始受到关注.

早在1857年人们就发现和验证了AMR效应^[4], 然而受限于薄膜技术的发展, 直到约百年后AMR效应才真正应用到传感器中. AMR效应产生的磁阻率较低, 因此在弱磁探测方面的能力不足, 但胜在制备成本低, 在磁传感器市场中仍有一席. GMR效应自1988年被首次发现之后^[5,6]很快便得到了商业化应用, 应用于硬盘驱动器的数据读取磁头, 极大提高了硬盘的面记录密度, 更重要的是与互补金属氧化物半导体(complementary metal oxide semiconductor, CMOS)技术的高兼容性使之获得广泛研究和应用. TMR效应的发现早于GMR效应^[7], 但直到1995年, 室温下可重复的隧穿磁阻效应被报道后^[8,9], 才唤起人们的研究热潮. TMR效应理论上能产生极高的磁阻率, 基于单晶MgO势垒的TMR磁阻率实验值不断提高, 一度达到604%^[10,11], 时至今日, 其薄膜结构和性能参数仍在不断优化^[12,13]. 表1对比了各类磁传感器之间的主要性能^[14]. 显然, TMR传感器相对于其他几类磁传感器, 有更高的灵敏度、更低的功耗和更宽的线性范围, 被认为是构建磁传感器的理想器件, 并且在多个领域有广阔的应有前景.

例如, 在生物医学检测以及辅助诊疗领域, 实现人体心磁图(magnetocardiography, MCG)和脑磁图(magnetoencephalography, MEG)信号的提取, 可以帮助人类加深对自身行为的认知^[15,16], 提高医疗健康服务水平. 然而, 心脏产生的磁场量级约在10^–12 T, 脑部神经元产生的磁场约在10^–15 T, 对传感器的探测能力要求极高. 相对于目前测量心、脑磁场常用的超导量子干涉仪(superconducting quantum interference device, SQUID), TMR传感器具有尺寸小、成本低、空间分辨率高等优点, 同时其检测灵敏度也可与SQUID相比拟, 在人体磁场探测方面具有非常大的潜力^[17]. 在导航定位及车辆监控方面, 通过检测车辆通过路面指定位置带来的地磁场扰动, 可以对车辆进行测速、分类, 得到如车速、车辆位置、流量、占用率等动态交通信息, 利用这些信息可以进一步规划交通灯控制、堵塞预警、事故预估、限速、停车位管理等工作, 可用于建立大规模交通监控和管理系统, 进而发展防碰撞、无人驾驶等应用, 极大方便了智能交通网络的构建^[18,19]. 在电流检测方面, TMR传感器可支撑频率高达10 MHz的交流电流以及直流电流的测试^[20], 适用于无接触式的多线电缆中的电流检测, 相较于传统的电流钳, 使用方便且无需过多维护, 因此常被应用于智能电网监测或智能制造中的功耗监测^[21]. 除此之外, 由于TMR传感器在高频交变磁场中表现出来的高灵敏度以及其可以实现非接触检测, 因此这类传感器也常用于导电材料中的无损检测^[22].

本文首先介绍TMR传感器的基本单元—磁隧道结(magnetic tunnel junction, MTJ), 阐述其对磁场进行线性感应的原理, 介绍基于磁隧道结的磁阻传感器结构设计以及工艺制备的关键技术, 并重点从灵敏度及噪声水平两方面探讨总结传感器性能优化的方法, 最后从自旋麦克风、生物医疗等新兴领域介绍TMR传感器应用情况, 对传感器的发展前景和应用潜力进行展望.

6. 总结与展望

基于磁阻效应的磁传感器在解决下一代高精度传感问题上起着至关重要的作用, 相对于AMR和GMR传感器, TMR传感器在灵敏度、尺寸、功耗等方面都具有明显优势. 如今, 通过膜层材料的进一步改善、集成磁通聚集器、合理的结构和电路设计优化, TMR传感器的性能仍在不断提升. 本文首先对TMR传感器的发展历史进行介绍, 通过对比不同原理磁传感器的性能指标, 表明了TMR传感器的性能优势. 接下来介绍了TMR传感器基本单元磁隧道结的结构, 并对实现传感器感应区域线性化的方法展开了详细的阐述. 为了提升传感器在不同温度环境下的稳定性, 通常使用惠斯通电桥结构以降低输出信号的温度漂移, 结合三维集成方法以满足空间磁场的探测需求. 探测精度是TMR传感器的重要性能指标, 决定了传感器对于微弱磁场探测的能力, 其主要受传感器灵敏度以及噪声影响. 本综述从理论出发, 总结了灵敏度和噪声的优化方法. 最后, 给出了TMR传感器在智能医疗以及自旋-MEMS学科交叉领域的新型应用实例.

近年来, TMR传感器依靠其巨大的性能优势取得了快速发展, 多家国内外电子企业都在研发和销售基于TMR效应的磁阻传感器, 例如美国的NVE科技, 日本的TDK, 德国的英飞凌, 中国的多维科技等公司. 然而, 作为下一代磁阻传感器发展的重点, TMR传感器仍存在许多亟需攻克的技术难点, 虽然其具有高灵敏度, 但远高于AMR, GMR传感器的低频噪声极大地影响了器件的信噪比, 限制了其探测微弱磁场的能力. 因此降低TMR传感器的输出噪声仍是研究热点之一. 与此同时, 实现高稳定性的惠斯通电桥结构和磁场三维检测, 仍需要对制备工艺进行一定优化, 以达到降低成本、提高检测精度的目的.

参考文献 (113)

隧穿磁阻传感器研究进展

通讯作者: E-mail: weisheng.zhao@buaa.edu.cn; E-mail: lengqw@bhqditi.com

Research progress of tunneling magnetoresistance sensor

Corresponding authors: E-mail: weisheng.zhao@buaa.edu.cn; E-mail: qunwen.leng@goertekusa.com

计量

隧穿磁阻传感器研究进展

通讯作者: E-mail: weisheng.zhao@buaa.edu.cn;

通讯作者: E-mail: lengqw@bhqditi.com

English Abstract

Research progress of tunneling magnetoresistance sensor

Corresponding author: E-mail: weisheng.zhao@buaa.edu.cn;

Corresponding authors: E-mail: qunwen.leng@goertekusa.com

全文HTML

2.1. 传感器的制备工艺

2.2. 传感器的线性化

2.3. 惠斯通电桥结构

2.4. 传感器的三维集成

2.5. 后端电路

3.1. 灵敏度

3.2. 探测精度

4.1. 噪声来源

4.2. 降低噪声的方法

4.2.1. 降低白噪声项

4.2.2. 降低磁噪声项

4.2.3. 降低电1/f噪声项

4.2.4. 抑制外接放大电路噪声

5.1. 自旋-MEMS麦克风

5.2. TMR生物传感器

目录

隧穿磁阻传感器研究进展

通讯作者: E-mail: weisheng.zhao@buaa.edu.cn; E-mail: lengqw@bhqditi.com

Research progress of tunneling magnetoresistance sensor

Corresponding authors: E-mail: weisheng.zhao@buaa.edu.cn; E-mail: qunwen.leng@goertekusa.com

计量

出版历程

隧穿磁阻传感器研究进展

通讯作者: E-mail: weisheng.zhao@buaa.edu.cn;

通讯作者: E-mail: lengqw@bhqditi.com

English Abstract

Research progress of tunneling magnetoresistance sensor

Corresponding author: E-mail: weisheng.zhao@buaa.edu.cn;

Corresponding authors: E-mail: qunwen.leng@goertekusa.com

全文HTML

2.1. 传感器的制备工艺

2.2. 传感器的线性化

2.3. 惠斯通电桥结构

2.4. 传感器的三维集成

2.5. 后端电路

3.1. 灵敏度

3.2. 探测精度

4.1. 噪声来源

4.2. 降低噪声的方法

4.2.1. 降低白噪声项

4.2.2. 降低磁噪声项

4.2.3. 降低电1/f噪声项

4.2.4. 抑制外接放大电路噪声

5.1. 自旋-MEMS麦克风

5.2. TMR生物传感器

目录