Ran He, Ph.D., 3D IC & Advanced Packaging
Project Researcher, Department of Precision Engineering, The University of Tokyo
Ɍesearch interests: low-temperature wafer bonding (especially surface activated bonding methods and Cu/adhesive and Cu/oxide hybrid bonding techniques), semiconductor advanced packaging, 3D interconnects, and 3D IC technology.
EXPERIENCE
Senior Engineer, Huawei Technologies Co., Ltd., Apr. 2018 — Present
Project Researcher, The University of Tokyo, Oct. 2015 — Mar. 2018
Department of Precision Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan
Research Subjects:
- Surface Activated Bonding (SAB) Methods
Combined SAB. Si-containing Ar beam and prebonding attach-detach procedure was combined to reduce bonding temperature of dielectric (like SiO2 and SiNx) and Cu films to sub-200 °C.
Modified SAB using Si nano-intermediate layer. Using in situ Ar beam bombardment and Si nano-intermediate layer deposition, bonding of semiconductors and dielectric can be obtained at room temperature.
Sequential Plasma Activation Bonding. Various combinations of O2 plasma, N2 plasma, and N radical activations are investigated for pre-bonding surface activation to improve the bonding energy achieved after post-bonding annealing at sub-200 °C.
H-containing HCOOH vapor treatment for sub-200 °C metal bonding/sintering.
Hydrophilic direct bonding (SiO2–SiO2, SiO2–SiNx, and glass–glass) at sub-200 °C
Cu/SiO2 Hybrid Bonding at sub-200 °C for 3D IC
Cu/Adhesive Hybrid Bonding at sub-200 °C for 2.5D/3D IC
Research Subjects: Combined surface activation approaches for
- Dielectric (SiO2-SiO2 and SiO2-SiNx) bonding and
- Cu/dielectric (SiO2, SiNx, polymer adheisve) hybrid bonding for 3D integration.
SPECIALIZED SKILLS
- Deep understanding and 5 years hands-on experience in low-temperature wafer bonding (room temperature to 200 °C) for semiconductor integration/advanced packaging/3D IC.
- 3 years hands-on experience in silicon wet chemical and reactive ion etching, metal film sputter deposition, wafer grinding/thinning, through-silicon via (TSV) formation and filling.
- Skilled in characterizations by using AFM, XPS, TEM, EDS, SAM, and bond strength measurements, etc.
- Fluent English and Chinese (Mandarin) in speaking and writing; good teamwork capability.
EDUCATION
Ph.D., Oct. 2012 — May 2016, Univ. of Tokyo
Department of Precision Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan
Supervisor: Tadamoto Suga
Thesis: Combined Surface Activation Approaches to Low-Temperature Wafer Bonding for 3D Integration.
- Development of new wafer surface activation methods for low-temperature (≤200 °C) dielectric (SiO2-SiO2 and SiO2-SiNx) and Cu/dielectric (Cu/adhesive and Cu/oxide) hybrid bonding,
- Chemical/mechanical/electrical/microstructure characterization of the bonding surface/interface, and
- Study of mechanisms of the surface activations and bonding.
Master, Sep. 2009 — Jul. 2012, IMECAS
Institute of Microelectronics, Chinese Academy of Sciences (CAS), Beijing, China
Supervisor: Daquan Yu
Research Subjects:
- Development of through-silicon vias (TSVs) filling process by using Cu-cored solder ball, in charge of the thermal-mechanical simulation, and process planning and running (photolithography, reactive ion etching, Ti/Cu sputtering deposition, TSV fill, etc.),
- Si-based 3D PN junction capacitor for passive integration on Si interposer, assisting the process optimizing and testing of the capacitor.
Bachelor, Sep. 2005 — Jul. 2009, HUST
Department of Electronic Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, China
One year of experience with Barium Strontium Titanate (Ba1-xSrxTiO3, BST) ferroelectric ceramics and SnO2 gas sensor research and development.
HONORS
- Award for Outstanding Student Presentation, 2014 ECS and SMEQ Joint International Meeting, P6: Semiconductor Wafer Bonding 13: Science, Technology, and Applications. Cancun, Mexico. October 5-9, 2014.
- Japanese Government (Monbukagakusho) Scholarship for Ph.D. study, Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, 2012-2015.
- Outstanding Paper Award, 2011 12th International Conference on Electronic Packaging Technology and High Density Packaging (ICEPT-HDP), Shanghai, China. August 8-11, 2011.