TY - CONF
T1 - Studies on SiO2-SiO2 bonding with hydrofluoric acid - room temperature and low stress bonding technique for MEMS
AU - Nakanishi, H.
AU - Nishimoto, T.
AU - Nakamura, R.
AU - Yotsumoto, A.
AU - Shoji, S.
N1 - Funding Information:
The authors would like to express their appreciation for Dr. R. Iwata (Tohoku University, Cyclotron and Radioisotope Center) who supported the evaluation using Radioisotope. A part of this work is partly supported by the Japanese Ministry of Education Science and Culture under a Grant-in-Aid for Scientific Research (B) No. 08455201 and (C) No. 09650491. Hiroaki Nakanishi received a BEng degree from Osaka University, Toyonaka, Japan, in 1982. From 1982, he was a researcher in Technology Research Laboratory, Shimadzu, Japan. Since 1997, he has been a principal researcher in Technology Research Laboratory, Shimadzu. He is working on micro fabricated sensors and devices. Takahiro Nishimoto received a BEng degree from Kyoto University, Kyoto, Japan, in 1989. He joined Shimadzu, in 1989. Ryousute Nakamura received a BEng degree from Waseda University, Tokyo, Japan, in 1997 and is currently a graduate student in the Department of Electronics, Information and Communication Engineering, of Waseda University. Akira Yotsumoto received a BEng degree from Waseda University, Tokyo, Japan, in 1997 and is currently a graduate student in the Department of Electronics, Information and Communication Engineering, of Waseda University. Tamio Yoshida received his PhD degree in Engineering from Osaka University, in 1976. He joined Shimadzu, in 1980. He has been a general manager of Technology Research Laboratory, Shimadzu, since 1993. Shuuichi Shoji received his PhD degree in Electronics Engineering from Tohoku University, Sendai, Japan, in 1984. Since 1997, he has been a professor in the Department of Electronics, Information and Communication Engineering, Waseda University.
PY - 1998
Y1 - 1998
N2 - Studies on SiO2-SiO2 bonding with hydrofluoric acid (HF) are described. This method has a remarkable feature that bonding can be obtained at room temperature. Advantages of this method are low thermal damage, low residual stress and simplicity of the bonding process, which are expected for the packaging and assembly of MEMS. The bond characteristics were measured under different bonding conditions of HF concentration, pressure, chemicals and so on. The bond strength depends on the applied pressure during bonding. HF concentration can be reduced to 0.1%. The bonding is also observed using KOH solution in stead of HF, TEM, SIMS, RI and EPMA were applied to evaluate the bonded interface. From the TEM results, an interlayer is formed between SiO2-SiO2. The thickness of the interlayer depends strongly on the applied pressure during bonding. The SIMS results showed that hydrogen and fluorine partially exist in the interlayer. Considering the result of the RI analysis, surplus HF solution is squeezed out from the interface as the bonding progress. From these results, both surfaces of the SiO2 are solved by HF and an interlayer, which is a binding layer, is formed. Formation of the interlayer plays a very important role for the characteristics of HF-bonding.
AB - Studies on SiO2-SiO2 bonding with hydrofluoric acid (HF) are described. This method has a remarkable feature that bonding can be obtained at room temperature. Advantages of this method are low thermal damage, low residual stress and simplicity of the bonding process, which are expected for the packaging and assembly of MEMS. The bond characteristics were measured under different bonding conditions of HF concentration, pressure, chemicals and so on. The bond strength depends on the applied pressure during bonding. HF concentration can be reduced to 0.1%. The bonding is also observed using KOH solution in stead of HF, TEM, SIMS, RI and EPMA were applied to evaluate the bonded interface. From the TEM results, an interlayer is formed between SiO2-SiO2. The thickness of the interlayer depends strongly on the applied pressure during bonding. The SIMS results showed that hydrogen and fluorine partially exist in the interlayer. Considering the result of the RI analysis, surplus HF solution is squeezed out from the interface as the bonding progress. From these results, both surfaces of the SiO2 are solved by HF and an interlayer, which is a binding layer, is formed. Formation of the interlayer plays a very important role for the characteristics of HF-bonding.
UR - http://www.scopus.com/inward/record.url?scp=0031676418&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031676418&partnerID=8YFLogxK
M3 - Paper
AN - SCOPUS:0031676418
SP - 609
EP - 614
T2 - Proceedings of the 1998 IEEE 11th Annual International Workshop on Micro Electro Mechanical Systems
Y2 - 25 January 1998 through 29 January 1998
ER -