TiN、Ti插入层对ITO与GaN欧姆接触性能影响的研究

人工晶体学报 ›› 2023, Vol. 52 ›› Issue (9): 1609-1616.

TiN、Ti插入层对ITO与GaN欧姆接触性能影响的研究

孟文利^1,2, 张育民^2,3,4, 孙远航², 王建峰^2,3,4, 徐科^1,2,3,4

1.中国科学技术大学国家示范性微电子学院,合肥 230026;
2.中国科学院苏州纳米技术与纳米仿生研究所,苏州 215123;
3.苏州纳维科技股份有限公司,苏州 215123;
4.江苏第三代半导体研究院,苏州 215000

收稿日期:2023-03-07 出版日期:2023-09-15 发布日期:2023-09-19
通信作者: 王建峰,博士,研究员。E-mail:jfwang2006@sinano.ac.cn
徐科,博士,研究员。E-mail:kxu2006@sinano.ac.cn
作者简介:孟文利(1993—),女,安徽省人,硕士研究生。E-mail:mengwl@mail.ustc.edu.cn
基金资助:
国家自然科学基金(12274360);国家重点研发计划(2022YFB3605402,2022YFB3604301,2022YFB3605200);苏州市重点产业技术创新项目(SGC2021081);江苏省重点研发计划(BE2020004,BE2021008)

Influence of TiN and Ti Insertion Layer on Ohmic Contact Performance Between ITO and GaN

MENG Wenli^1,2, ZHANG Yumin^2,3,4, SUN Yuanhang², WANG Jianfeng^2,3,4, XU Ke^1,2,3,4

1. School of Microelectronics, University of Science and Technology of China, Hefei 230026, China;
2. Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China;
3. Suzhou Nanowin Science and Technology Co., Ltd., Suzhou 215123, China;
4. Jiangsu Institute of Advanced Semiconductors Ltd., Suzhou 215000, China

Received:2023-03-07 Online:2023-09-15 Published:2023-09-19

摘要/Abstract

摘要： 透明半导体铟锡氧化物(ITO)作为电极能够降低光导开关电极边缘电流集聚效应和提高脉冲激光的利用率。本文通过在ITO与GaN界面之间分别插入10 nm的Ti与TiN,研究Ti、TiN对ITO与GaN欧姆接触性能的影响。I-V测试结果表明,随着退火温度升高,插入TiN的光导开关一直保持欧姆接触特性,而插入Ti的光导开关由欧姆接触转变为肖特基接触。通过TEM测试发现,当以Ti作为插入层时,ITO通过插入层向插入层与GaN的界面扩散,在接触界面形成Ti的氧化物及空洞。透射光谱显示,不同退火温度下插入Ti层的透过率均低于38.3%,而以TiN作为插入层时透过率为38.8%~55.0%。因此含有TiN的光导开关具有更稳定的电学性能和更高的透过率,这为GaN光导开关在高温高功率领域的应用提供了参考。

关键词: GaN光导开关, ITO, Ti, TiN, 欧姆接触

Abstract: The electrode made of transparent semiconductor indium tin oxide (ITO) can reduce the edge current crowding effect of photoconductive semiconductor switches and improve the utilization of pulse laser. In this paper, 10 nm Ti and TiN layer were inserted into the interface between ITO and GaN, and the influences of Ti and TiN layer on the Ohmic contact performance between ITO and GaN were studied. I-V test results show that with the increase of the annealing temperature, the GaN photoconductive semiconductor switch with Ti insertion layer changes from Ohmic contact to Schottky contact, while the photoconductive semiconductor switch with TiN insertion layer keeps Ohmic contact characteristics. TEM observation shows that when Ti is used as the insertion layer, ITO diffuses through the insertion layer to the interface between the insertion layer and GaN, resulting in the formation of Ti oxide and holes at the interface. The transmission spectra show that the transmittance of samples with Ti insertion layer is less than 38.3% at different annealing temperatures, while the transmittance is 38.8%~55.0% when TiN is used as the insertion layer. Therefore, the photoconductive semiconductor switch containing TiN insertion layer shows a higher thermal stability and transmittance, which provides reference for the application of GaN photoconductive semiconductor switch in the field of high temperature and high power.

Key words: GaN photoconductive semiconductor switch, ITO, Ti, TiN, Ohmic contact

中图分类号:

O472⁺.4

孟文利, 张育民, 孙远航, 王建峰, 徐科. TiN、Ti插入层对ITO与GaN欧姆接触性能影响的研究[J]. 人工晶体学报, 2023, 52(9): 1609-1616.

MENG Wenli, ZHANG Yumin, SUN Yuanhang, WANG Jianfeng, XU Ke. Influence of TiN and Ti Insertion Layer on Ohmic Contact Performance Between ITO and GaN[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2023, 52(9): 1609-1616.

参考文献

[1] WANG W, XIA L S, CHEN Y, et al. Research on synchronization of 15 parallel high gain photoconductive semiconductor switches triggered by high power pulse laser diodes[J]. Applied Physics Letters, 2015, 106(2): 022108.
[2] VERGNE B, COUDERC V, BARTHELEMY A, et al. High-voltage rectifier diodes used as photoconductive device for microwave pulse generation[J]. IEEE Transactions on Plasma Science, 2006, 34(5): 1806-1813.
[3] SHI W, ZHANG L, GUI H M, et al. Accurate measurement of the jitter time of GaAs photoconductive semiconductor switches triggered by a one-to-two optical fiber[J]. Applied Physics Letters, 2013, 102(15): 154106.
[4] NUNNALLY W C. Critical component requirements for compact pulse power system architectures[J]. IEEE Transactions on Plasma Science, 2005, 33(4): 1262-1267.
[5] HU L, SU J C, DING Z J, et al. Note: all solid-state high repetitive sub-nanosecond risetime pulse generator based on bulk gallium arsenide avalanche semiconductor switches[J]. The Review of Scientific Instruments, 2016, 87(8): 086107.
[6] 张育民, 王建峰, 蔡德敏, 等. 氢化物气相外延生长氮化镓单晶衬底的研究进展[J]. 人工晶体学报, 2020, 49(11): 1970-1983.
ZHANG Y M, WANG J F, CAI D M, et al. Progress on GaN single crystal substrate grown by hydride vapor phase epitaxy[J]. Journal of Synthetic Crystals, 2020, 49(11): 1970-1983 (in Chinese).
[7] MAJDA-ZDANCEWICZ E, SUPRONIUK M, PAWŁOWSKI M, et al. Current state of photoconductive semiconductor switch engineering[J]. Opto-Electronics Review, 2018, 26(2): 92-102.
[8] LUAN C B, LI H T. Influence of hot-carriers on the on-state resistance in Si and GaAs photoconductive semiconductor switches working at long pulse width[J]. Chinese Physics Letters, 2020, 37(4): 044203.
[9] SHEU J K, SU Y K, CHI G C, et al. Effects of thermal annealing on the indium tin oxide Schottky contacts of n-GaN[J]. Applied Physics Letters, 1998, 72(25): 3317-3319.
[10] HWANG J D, YANG G H, LIN C C, et al. Nonalloyed Ti/indium tin oxide and Ti ohmic contacts to n-type GaN using plasma pre-treatment[J]. Solid-State Electronics, 2006, 50(2): 297-299.
[11] HSIAO W H, CHEN T H, LAI L W, et al. Investigations on the cosputtered ITO-ZnO transparent electrode ohmic contacts to n-GaN[J]. Applied Sciences, 2016, 6(2): 60.
[12] ZHU Y F, HUANG R, LI Z C, et al. Interface analysis of TiN/n-GaN Ohmic contacts with high thermal stability[J]. Applied Surface Science, 2019, 481: 1148-1153.
[13] LU C J, DAVYDOV A V, JOSELL D, et al. Interfacial reactions of Ti/n-GaN contacts at elevated temperature[J]. Journal of Applied Physics, 2003, 94(1): 245-253.
[14] SHIM K H, PAEK M C, LEE B T, et al. Preferential regrowth of indium-tin oxide (ITO) films deposited on GaN (0001) by RF-magnetron sputter[J]. Applied Physics A, 2001, 72(4): 471-474.
[15] GRECO G, IUCOLANO F, ROCCAFORTE F. Ohmic contacts to gallium nitride materials[J]. Applied Surface Science, 2016, 383: 324-345.
[16] RUVIMOV S, LILIENTAL-WEBER Z, WASHBURN J, et al. Microstructure of Ti/Al and Ti/Al/Ni/Au ohmic contacts for n-GaN[J]. Applied Physics Letters, 1996, 69(11): 1556-1558.
[17] ZHANG R Y, MA Q Y, LIU H G, et al. Crystal orientation-dependent oxidation of epitaxial TiN films with tunable plasmonics[J]. ACS Photonics, 2021, 8(3): 847-856.
[18] LIU X K, WANG H F, WU J Y, et al. Vertical GaN Schottky barrier diode with record low contact resistivity on N-polarity using ultrathin ITO interfacial layer[J]. IEEE Transactions on Electron Devices, 2023, 70(4): 1601-1606.
[19] JENKINS D W, REN S Y, DOW J D. Dependence on uniaxial stress of deep levels in Ⅲ-Ⅴ compound and group-Ⅳ elemental semiconductors[J]. Physical Review B, 1989, 39(11): 7881-7894.
[20] HORNG R H, WUU D S, LIEN Y C, et al. Low-resistance and high-transparency Ni/indium tin oxide ohmic contacts to p-type GaN[J]. Applied Physics Letters, 2001, 79(18): 2925-2927.
[21] LOOK D C, FARLOW G C, DREVINSKY P J, et al. On the nitrogen vacancy in GaN[J]. Applied Physics Letters, 2003, 83(17): 3525-3527.
[22] JENKINS D W, DOW J D. Electronic-structures and doping of InN, In_xGa_1-xN, and In_xAl_1-xN[J]. Physical Review B, 1989, 39(5): 3317-3329.
[23] KIM S J, NAM T Y, KIM T G. Low-resistance nonalloyed Ti/Al ohmic contacts on N-face n-type GaN via an O₂ plasma treatment[J]. IEEE Electron Device Letters, 2011, 32(2): 149-151.
[24] VAN DAELE B, VAN TENDELOO G, RUYTHOOREN W, et al. The role of Al on Ohmic contact formation on n-type GaN and AlGaN/GaN[J]. Applied Physics Letters, 2005, 87(6): 061905.