SEMICONDUCTOR DEVICES

Breakdown voltage enhancement of AlGaN/GaN high electron mobility transistors by polyimide/chromium composite thin film passivation

Futong Chu, Chao Chen and Xingzhao Liu

+ Author Affiliations

 Corresponding author: Chu Futong, Email:cft1228@163.com

PDF

Abstract: A novel AlGaN/GaN high electric mobility transistor (HEMT) with polyimide (PI)/chromium (Cr) as the passivation layer is proposed for enhancing breakdown voltage and its DC performance is also investigated. The Cr nanoparticles firstly introduced in PI thin films by the co-evaporation can be used to increase the permittivity of PI film. The high-permittivity PI/Cr passivation acting as field plate can suppress the fringing electric field peak at the drain-side edge of the gate electrode. This mechanism is demonstrated in accord with measured results. The experimental results show that in comparison with the AlGaN/GaN HEMTs without passivation, the breakdown voltage of HEMTs with the PI/Cr composite thin films can be significantly improved, from 122 to 248 V.

Key words: AlGaN/GaNbreakdown voltagehigh-electron-mobility transistorspolyimide



[1]
Kumar V, Lu W, Schwindt R, et al. AlGaN/GaN HEMTs on SiC with fT of over 120 GHz. IEEE Electron Device Lett, 2002, 23(8):455 doi: 10.1109/LED.2002.801303
[2]
Wang Zhigang, Chen Wanjun, Zhang Bo, et al. A novel controllable hybrid-anode AlGaN/GaN field-effect rectifier with low operation voltage. Chin Phys Lett, 2012, 29(10):107202 doi: 10.1088/0256-307X/29/10/107202
[3]
Yang Ling, Hao Yue, Ma Xiaohua, et al. Various recipes of SiNx passivated AlGaN/GaN high electron mobility transistors in correlation with current slump. Chin Phys Lett, 2009, 26(11):117104 doi: 10.1088/0256-307X/26/11/117104
[4]
Cheng Zhiqun, Liu Jie, Zhou Yugang, et al. Broadband microwave noise characteristics of high-linearity composite-channel Al0.3Ga0.7N/Al0.05Ga0.95N/GaN HEMTs. IEEE Electron Device Lett, 2005, 26(8):145
[5]
Xing H, Dora Y, Chini A, et al. High breakdown voltage AlGaN-GaN HEMTs achieved by multiple field plates. IEEE Electron Device Lett, 2004, 25(4):161 doi: 10.1109/LED.2004.824845
[6]
Karmalkar S, Mishra U K. Enhancement of breakdown voltage in AlGaN/GaN high electron mobility transistors using a field plate. IEEE Electron Device Lett, 2001, 48(8):1515 doi: 10.1109/16.936500
[7]
Zhang N Q, Keller S, Parish G, et al. High breakdown GaN HEMT with overlapping gate structure. IEEE Electron Device Lett, 2000, 21(9):421 doi: 10.1109/55.863096
[8]
Kim Y S, Lim J, Seok O G, et al. High breakdown voltage AlGaN/GaN HEMT by employing selective fluoride plasma treatment. Power Semiconductor Devices and ICs (ISPSD). IEEE 23rd International Symposium, 2011:251 http://ieeexplore.ieee.org/document/5890838/authors
[9]
Song Di, Liu Jie, Cheng Zhiquan, et al. Normally off AlGaN/GaN low-density drain HEMT (LDD-HEMT) with enhanced breakdown voltage and reduced current collapse. IEEE Electron Device Lett, 2007, 28:189 doi: 10.1109/LED.2007.891281
[10]
Chen Xingbi. Lateral high-voltage semiconductor devices with surface covered by thin film of dielectric material with high permittivity. USA Patent, No. 6936907, 2005, Aug. 30
[11]
Li Junhong, Li Ping, Huo Weirong, et al. Analysis and fabrication of an LDMOS with high-permittivity dielectric. IEEE Electron Device Lett, 2011, 33(9):1266 http://ieeexplore.ieee.org/document/5957260/
[12]
Karmalkar S, Shur M S, Simin G, et al. Field-plate engineering for HFETs. IEEE Electron Device Lett, 2005, 52(12):2534 doi: 10.1109/TED.2005.859568
[13]
Hampson M D, Shen S C, Schwindt R S, et al. Polyimide passivated AlGaN/GaN HFETs with 7.65 W/mm at 18 GHz. IEEE Electron Device Lett, 2004, 25:238 doi: 10.1109/LED.2004.826565
[14]
Tian B, Chen C, Zhang J, et al. Structure and electrical characteristics of AlGaN/GaN MISHFET with Al2O3 thin film as both surface passivation and gate dielectric. Semicond Sci Technol, 2011, 26:085023 doi: 10.1088/0268-1242/26/8/085023
[15]
Tan I H, Sinder G L, Hu E L. A self-consistent solution of Schrödinger-Poisson equations using a nonuniform mesh. J Appl Phys, 1990, 68(8):4071 doi: 10.1063/1.346245
Fig. 1.  Schematic of AlGaN/GaN HEMTs (off-state) and the electric filed distribution. (a) HEMT without passivation (partially depletion). (b) HEMT with PI passivation (partially depletion). (c) HEMT with PI/Cr passivation (partially depletion). (d) The electric filed distribution (breakdown).

Fig. 2.  Comparison of the gate leakage current for the un-passivated AlGaN/GaN HEMTs and passivated AlGaN/GaN HEMTs by PI and PI/Cr thin films.

Fig. 3.  Typical output ($I_{\rm DS}$-$V_{\rm DS})$ characteristics with varying gate biases of (a) un-passivated, (b) PI thin film passivated and (c) PI/Cr thin film passivated AlGaN/GaN HEMTs.

Fig. 4.  Transfer characteristics of the un-passivated AlGaN/GaN HEMTs and AlGaN/GaN HEMTs passivated by PI and PI/Cr thin films at $V_{\rm DS}$ $=$ 10 V.

Fig. 5.  Off-state breakdown voltage of AlGaN/GaN HEMTs with and without passivation at 1 mA/mm.

Fig. 6.  Permittivity of the PI/Cr composite thin films as a function of Cr volume fraction at 10$^{3}$ Hz and room temperature. The inset shows metallic Cr particles in the PI thin films analyzed by energy dispersive X-ray spectroscopy (EDX).

[1]
Kumar V, Lu W, Schwindt R, et al. AlGaN/GaN HEMTs on SiC with fT of over 120 GHz. IEEE Electron Device Lett, 2002, 23(8):455 doi: 10.1109/LED.2002.801303
[2]
Wang Zhigang, Chen Wanjun, Zhang Bo, et al. A novel controllable hybrid-anode AlGaN/GaN field-effect rectifier with low operation voltage. Chin Phys Lett, 2012, 29(10):107202 doi: 10.1088/0256-307X/29/10/107202
[3]
Yang Ling, Hao Yue, Ma Xiaohua, et al. Various recipes of SiNx passivated AlGaN/GaN high electron mobility transistors in correlation with current slump. Chin Phys Lett, 2009, 26(11):117104 doi: 10.1088/0256-307X/26/11/117104
[4]
Cheng Zhiqun, Liu Jie, Zhou Yugang, et al. Broadband microwave noise characteristics of high-linearity composite-channel Al0.3Ga0.7N/Al0.05Ga0.95N/GaN HEMTs. IEEE Electron Device Lett, 2005, 26(8):145
[5]
Xing H, Dora Y, Chini A, et al. High breakdown voltage AlGaN-GaN HEMTs achieved by multiple field plates. IEEE Electron Device Lett, 2004, 25(4):161 doi: 10.1109/LED.2004.824845
[6]
Karmalkar S, Mishra U K. Enhancement of breakdown voltage in AlGaN/GaN high electron mobility transistors using a field plate. IEEE Electron Device Lett, 2001, 48(8):1515 doi: 10.1109/16.936500
[7]
Zhang N Q, Keller S, Parish G, et al. High breakdown GaN HEMT with overlapping gate structure. IEEE Electron Device Lett, 2000, 21(9):421 doi: 10.1109/55.863096
[8]
Kim Y S, Lim J, Seok O G, et al. High breakdown voltage AlGaN/GaN HEMT by employing selective fluoride plasma treatment. Power Semiconductor Devices and ICs (ISPSD). IEEE 23rd International Symposium, 2011:251 http://ieeexplore.ieee.org/document/5890838/authors
[9]
Song Di, Liu Jie, Cheng Zhiquan, et al. Normally off AlGaN/GaN low-density drain HEMT (LDD-HEMT) with enhanced breakdown voltage and reduced current collapse. IEEE Electron Device Lett, 2007, 28:189 doi: 10.1109/LED.2007.891281
[10]
Chen Xingbi. Lateral high-voltage semiconductor devices with surface covered by thin film of dielectric material with high permittivity. USA Patent, No. 6936907, 2005, Aug. 30
[11]
Li Junhong, Li Ping, Huo Weirong, et al. Analysis and fabrication of an LDMOS with high-permittivity dielectric. IEEE Electron Device Lett, 2011, 33(9):1266 http://ieeexplore.ieee.org/document/5957260/
[12]
Karmalkar S, Shur M S, Simin G, et al. Field-plate engineering for HFETs. IEEE Electron Device Lett, 2005, 52(12):2534 doi: 10.1109/TED.2005.859568
[13]
Hampson M D, Shen S C, Schwindt R S, et al. Polyimide passivated AlGaN/GaN HFETs with 7.65 W/mm at 18 GHz. IEEE Electron Device Lett, 2004, 25:238 doi: 10.1109/LED.2004.826565
[14]
Tian B, Chen C, Zhang J, et al. Structure and electrical characteristics of AlGaN/GaN MISHFET with Al2O3 thin film as both surface passivation and gate dielectric. Semicond Sci Technol, 2011, 26:085023 doi: 10.1088/0268-1242/26/8/085023
[15]
Tan I H, Sinder G L, Hu E L. A self-consistent solution of Schrödinger-Poisson equations using a nonuniform mesh. J Appl Phys, 1990, 68(8):4071 doi: 10.1063/1.346245
  • Search

    Advanced Search >>

    GET CITATION

    shu

    Export: BibTex EndNote

    Article Metrics

    Article views: 2492 Times PDF downloads: 18 Times Cited by: 0 Times

    History

    Received: 14 September 2013 Revised: 25 October 2013 Online: Published: 01 March 2014

    Catalog

      Email This Article

      User name:
      Email:*请输入正确邮箱
      Code:*验证码错误
      Futong Chu, Chao Chen, Xingzhao Liu. Breakdown voltage enhancement of AlGaN/GaN high electron mobility transistors by polyimide/chromium composite thin film passivation[J]. Journal of Semiconductors, 2014, 35(3): 034007. doi: 10.1088/1674-4926/35/3/034007 F T Chu, C Chen, X Z Liu. Breakdown voltage enhancement of AlGaN/GaN high electron mobility transistors by polyimide/chromium composite thin film passivation[J]. J. Semicond., 2014, 35(3): 034007. doi: 10.1088/1674-4926/35/3/034007.Export: BibTex EndNote
      Citation:
      Futong Chu, Chao Chen, Xingzhao Liu. Breakdown voltage enhancement of AlGaN/GaN high electron mobility transistors by polyimide/chromium composite thin film passivation[J]. Journal of Semiconductors, 2014, 35(3): 034007. doi: 10.1088/1674-4926/35/3/034007

      F T Chu, C Chen, X Z Liu. Breakdown voltage enhancement of AlGaN/GaN high electron mobility transistors by polyimide/chromium composite thin film passivation[J]. J. Semicond., 2014, 35(3): 034007. doi: 10.1088/1674-4926/35/3/034007.
      Export: BibTex EndNote

      Breakdown voltage enhancement of AlGaN/GaN high electron mobility transistors by polyimide/chromium composite thin film passivation

      doi: 10.1088/1674-4926/35/3/034007
      Funds:

      the Research Foundation for the Doctoral Program of Higher Education of China 2012018530003

      Project supported by the National Natural Science Foundation of China (No. 50932002) and the Research Foundation for the Doctoral Program of Higher Education of China (No. 2012018530003)

      the National Natural Science Foundation of China 50932002

      More Information
      • Corresponding author: Chu Futong, Email:cft1228@163.com
      • Received Date: 2013-09-14
      • Revised Date: 2013-10-25
      • Published Date: 2014-03-01

      Catalog

        /

        DownLoad:  Full-Size Img  PowerPoint
        Return
        Return