Role of Thin Sn Layer for Low Temperature Al-Al Thermo-compression Bonding of Wafer-level Hermetic Sealing
-
- Satoh Shiro
- Micro System Integration Center, Tohoku University
-
- Fukushi Hideyuki
- Micro System Integration Center, Tohoku University
-
- Esashi Masayoshi
- Micro System Integration Center, Tohoku University
-
- Tanaka Shuji
- Micro System Integration Center, Tohoku University Graduate School of Engineering, Tohoku University
Bibliographic Information
- Other Title
-
- 低温Al-Al熱圧着ウェハレベル真空封止接合における薄膜Sn層の役割
- テイオン Al-Al ネツ アッチャク ウェハレベル シンクウ フウシ セツゴウ ニ オケル ハクマク Snソウ ノ ヤクワリ
Search this article
Description
<p>This paper reports low temperature hermetic wafer bonding using Al/Sn/Al/Sn/Al as a bonding layer. The Al surface of the bonding layer was oxidized in air, but hermetic sealing was demonstrated without surface treatment at 370∼390ºC, which was lower than the maximum temperature of CMOS backend process (400ºC). For the successfully sealed samples, the bonding layer was considerably compressed and squeezed, and the remaining thickness was only <16% of the initial one, i.e. the reduction rate was >84%. On the other hand, the samples without Sn layers inserted, i.e. using a pure Al bonding layer, were not hermetically sealed at similar temperatures, showing the reduction rate smaller than 70%. A clear correlation between the reduction rate and the yield of hermetic sealing was observed. Taking account of analytical results and Al-Sn phase diagram, it is suggested that Al-Sn liquid phase in Al grain boundaries enhances the grain slip deformation of the bonding layer and fractionates the surface Al oxide layer during the bonding process. The function of Sn for Al-Al bonding suggested in this paper is useful for wafer-level hermetic MEMS packaging at low temperature.</p>
Journal
-
- IEEJ Transactions on Sensors and Micromachines
-
IEEJ Transactions on Sensors and Micromachines 137 (12), 432-437, 2017
The Institute of Electrical Engineers of Japan
- Tweet
Keywords
Details 詳細情報について
-
- CRID
- 1390282679439541248
-
- NII Article ID
- 130006235313
-
- NII Book ID
- AN1052634X
-
- ISSN
- 13475525
- 13418939
-
- NDL BIB ID
- 028724531
-
- Text Lang
- ja
-
- Data Source
-
- JaLC
- NDL
- Crossref
- CiNii Articles
-
- Abstract License Flag
- Disallowed