Surface activated bonding explained

Surface activated bonding (SAB) is a non-high-temperature wafer bonding technology with atomically clean and activated surfaces. Surface activation prior to bonding by using fast atom bombardment is typically employed to clean the surfaces. High-strength bonding of semiconductor, metal, and dielectric can be obtained even at room temperature.[1] [2]

Overview

In the standard SAB method, wafer surfaces are activated by argon fast atom bombardment in ultra-high vacuum (UHV) of 10−4–10−7 Pa. The bombardment removes adsorbed contaminants and native oxides on the surfaces. The activated surfaces are atomically clean and reactive for formation of direct bonds between wafers when they are brought into contact even at room temperature.

Researches on SAB

The SAB method has been studied for bonding of various materials, as shown in Table I.

Table I. Studies of standard SAB for various materials!!Si!Ge!GaAs!SiC!Cu!Al2O3!SiO2
Si[3] [4] [5]
Ge
GaAs
SiC
Cu
Al2O3
SiO2Failure
The standard SAB, however, failed to bond some materials such as SiO2 and polymer films. The modified SAB was developed to solve this problem, by using a sputtering deposited Si intermediate layer to improve the bond strength.
Table II. Modified SAB with Si intermediate layer!!Bonding intermediate layer!References
SiO2-SiO2Sputtered Fe-Si on SiO2[6]
Polymer filmsSputtered Fe-Si on both sides[7]
Si-SiCSputtered Si on SiC
Si-SiO2Sputtered Si on SiO2[8]
The combined SAB has been developed for SiO2-SiO2 and Cu/SiO2 hybrid bonding, without use of any intermediate layer.
Table III. Combined SAB using Si-containing Ar beam!!Bond interface!References
SiO2-SiO2Direct bond interface
Cu-Cu, SiO2-SiO2, SiO2-SiNxdirect bond interface

Technical specifications

Materials
Advantages
  • Low process temperature: room temperature–200 °C
  • No concerns of thermal stress and damages
  • High bonding quality
  • Semiconductor and metal bonding interfaces without oxides
  • Completely dry process without wet chemical cleaning
  • Process compatibility to semiconductor technology
Drawbacks
  • High vacuum level (10−4–10−7 Pa)

Notes and References

  1. Web site: Room Temperature Wafer Bonding Machine BOND MEISTER｜Mitsubishi Heavy Industries Machine Tool Co., Ltd.. www.mhi-machinetool.com.
  2. Web site: MHI Develops World's First 12-inch Wafer Bonding Machine | Mitsubishi Heavy Industries, Ltd. Global Website. Mitsubishi Heavy Industries. Ltd. Mitsubishi Heavy Industries, Ltd.. 16 January 2012 .
  3. J. Liang, T. Miyazaki, M. Morimoto, S. Nishida, N. Watanabe, and N. Shigekawa, “Electrical Properties of p-Si/n-GaAs Heterojunctions by Using Surface-Activated Bonding,” Appl. Phys. Express, vol. 6, no. 2, p. 021801, Feb. 2013. Available
  4. H. Takagi, J. Utsumi, M. Takahashi, and R. Maeda, “Room-Temperature Bonding of Oxide Wafers by Ar-beam Surface Activation,” ECS Trans., vol. 16, no. 8, pp. 531–537, Oct. 2008. Available
  5. Ichikawa. Masatsugu. Fujioka. Akira. Kosugi. Takao. Endo. Shinya. Sagawa. Harunobu. Tamaki. Hiroto. Mukai. Takashi. Uomoto. Miyuki. Shimatsu. Takehito. High-output-power deep ultraviolet light-emitting diode assembly using direct bonding. Applied Physics Express. 9. 7. 072101. 10.7567/apex.9.072101. 2016APExp...9g2101I. 2016. 100054996 .
  6. R. Kondou and T. Suga, “Room temperature SiO2 wafer bonding by adhesion layer method,” presented at the Electronic Components and Technology Conference (ECTC), 2011 IEEE 61st, 2011, pp. 2165–2170. Available
  7. T. Matsumae, M. Fujino, and T. Suga, “Room-temperature bonding method for polymer substrate of flexible electronics by surface activation using nano-adhesion layers,” Japanese Journal of Applied Physics, vol. 54, no. 10, p. 101602, Oct. 2015. Available
  8. K. Tsuchiyama, K. Yamane, H. Sekiguchi, H. Okada, and A. Wakahara, “Fabrication of Si/SiO2/GaN structure by surface-activated bonding for monolithic integration of optoelectronic devices,” Japanese Journal of Applied Physics, vol. 55, no. 5S, p. 05FL01, May 2016. Available
  9. Takagi. H.. Kikuchi. K.. Maeda. R.. Chung. T. R.. Suga. T.. 1996-04-15. Surface activated bonding of silicon wafers at room temperature. Applied Physics Letters. 68. 16. 2222–2224. 10.1063/1.115865. 1996ApPhL..68.2222T. 0003-6951.
  10. Wang. Chenxi. Suga. Tadatomo. 2011-05-01. Room-Temperature Direct Bonding Using Fluorine Containing Plasma Activation. Journal of the Electrochemical Society. en. 158. 5. H525–H529. 10.1149/1.3560510. 97977240 . 0013-4651.
  11. Higurashi. Eiji. Sasaki. Yuta. Kurayama. Ryuji. Suga. Tadatomo. Doi. Yasuo. Sawayama. Yoshihiro. Hosako. Iwao. 2015-03-01. Room-temperature direct bonding of germanium wafers by surface-activated bonding method. Japanese Journal of Applied Physics. en. 54. 3. 030213. 10.7567/jjap.54.030213. 2015JaJAP..54c0213H. free.
  12. Higurashi. Eiji. Okumura. Ken. Nakasuji. Kaori. Suga. Tadatomo. 2015-03-01. Surface activated bonding of GaAs and SiC wafers at room temperature for improved heat dissipation in high-power semiconductor lasers. Japanese Journal of Applied Physics. en. 54. 3. 030207. 10.7567/jjap.54.030207. 2015JaJAP..54c0207H. free.
  13. Mu. F.. Iguchi. K.. Nakazawa. H.. Takahashi. Y.. Fujino. M.. Suga. T.. Direct Wafer Bonding of SiC-SiC by SAB for Monolithic Integration of SiC MEMS and Electronics. ECS Journal of Solid State Science and Technology. 30 June 2016. 5. 9. P451–P456. 10.1149/2.0011609jss.
  14. Liang. J.. Nishida. S.. Arai. M.. Shigekawa. N.. 2014-04-21. Effects of thermal annealing process on the electrical properties of p+-Si/n-SiC heterojunctions. Applied Physics Letters. 104. 16. 161604. 10.1063/1.4873113. 2014ApPhL.104p1604L. 56359750. 0003-6951.
  15. Mu. Fengwen. Iguchi. Kenichi. Nakazawa. Haruo. Takahashi. Yoshikazu. Fujino. Masahisa. Suga. Tadatomo. 2016-04-01. Room-temperature wafer bonding of SiC–Si by modified surface activated bonding with sputtered Si nanolayer. Japanese Journal of Applied Physics. en. 55. 4S. 04EC09. 10.7567/jjap.55.04ec09. 2016JaJAP..55dEC09M. 124719605 .
  16. Kim. T. H.. Howlader. M. M. R.. Itoh. T.. Suga. T.. 2003-03-01. Room temperature Cu–Cu direct bonding using surface activated bonding method. Journal of Vacuum Science & Technology A. 21. 2. 449–453. 10.1116/1.1537716. 2003JVST...21..449K. 98719282. 0734-2101.
  17. Shigetou. A.. Itoh. T.. Matsuo. M.. Hayasaka. N.. Okumura. K.. Suga. T.. 2006-05-01. Bumpless interconnect through ultrafine Cu electrodes by means of surface-activated bonding (SAB) method. IEEE Transactions on Advanced Packaging. 29. 2. 218–226. 10.1109/TADVP.2006.873138. 27663896. 1521-3323.
  18. Matsumae. Takashi. Nakano. Masashi. Matsumoto. Yoshiie. Suga. Tadatomo. 2013-03-15. Room Temperature Bonding of Polymer to Glass Wafers Using Surface Activated Bonding (SAB) Method. ECS Transactions. en. 50. 7. 297–302. 10.1149/05007.0297ecst. 2013ECSTr..50g.297M . 1938-6737.
  19. Book: Takeuchi. K.. Fujino. M.. Suga. T.. Koizumi. M.. Someya. T.. 2015 IEEE 65th Electronic Components and Technology Conference (ECTC) . Room temperature direct bonding and debonding of polymer film on glass wafer for fabrication of flexible electronic devices . 2015-05-01. 700–704. 10.1109/ECTC.2015.7159668. 978-1-4799-8609-5. 11395361.
  20. He. Ran. Fujino. Masahisa. Yamauchi. Akira. Suga. Tadatomo. 2016-04-01. Combined surface-activated bonding technique for low-temperature hydrophilic direct wafer bonding. Japanese Journal of Applied Physics. en. 55. 4S. 04EC02. 10.7567/jjap.55.04ec02. 2016JaJAP..55dEC02H. 123656692 .
  21. He. Ran. Fujino. Masahisa. Yamauchi. Akira. Suga. Tadatomo. 2015-03-01. Novel hydrophilic SiO2 wafer bonding using combined surface-activated bonding technique. Japanese Journal of Applied Physics. en. 54. 3. 030218. 10.7567/jjap.54.030218. 2015JaJAP..54c0218H. 119520218 . free.
  22. He. Ran. Fujino. Masahisa. Yamauchi. Akira. Wang. Yinghui. Suga. Tadatomo. 2016-01-01. Combined Surface Activated Bonding Technique for Low-Temperature Cu/Dielectric Hybrid Bonding. ECS Journal of Solid State Science and Technology. en. 5. 7. P419–P424. 10.1149/2.0201607jss. 101149612. 2162-8769.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Surface activated bonding".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.