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- Bengtsson, Stefan, 1961, et al.
(author)
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Integration of silicon and diamond, aluminum nitride or aluminum oxide for electronic materials
- 1999
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In: conference proceedings:III-V and IV-IV Materials and Processing Challenges for Highly Integrated Microelectronics and Optoelectronics. Symposium.. ; , s. 133-
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Conference paper (peer-reviewed)abstract
- Material integration for the formation of advanced silicon-on-insulator materials by wafer bonding and etch-back is discussed. Wafer bonding allows the combining of materials that it is not possible to grow on top of each other by any other technique. In our experiments, polycrystalline diamond, aluminum nitride or aluminum oxide films with thickness of 0.1-5 μm were deposited on silicon wafers. Bonding experiments were made with these films to bare silicon wafers with the goal of forming silicon-on-insulator structures with buried films of polycrystalline diamond, aluminum nitride or aluminum oxide. These silicon-on-insulator structures are intended to address self-heating effects in conventional silicon-on-insulator materials with buried layers of silicon dioxide. The surfaces of the deposited diamond films were, by order of magnitude, too rough to allow direct bonding to a silicon wafer. In contrast the deposited aluminum nitride and aluminum oxide films did allow direct bonding to silicon. Bonding of the diamond surface to silicon was instead made through a deposited and polished layer of polycrystalline silicon on top of the diamond. In the case of the aluminum nitride electrostatic bonding was also demonstrated. Further, the compatibility of these insulators to silicon process technology was investigated
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- Bergh, Mats, 1968, et al.
(author)
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The influence of surface micro-roughness on bondability
- 1995
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In: Proceedings of the Third International Symposium on Semiconductor Wafer Bonding: Physics and Applications. ; , s. 126-
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Conference paper (peer-reviewed)abstract
- The requirements on a surface in terms of micro-roughness necessary to achieve spontaneous bonding on wafer contact have been investigated. Wafers from four different manufacturers, all having their special surface characteristics, were evaluated using atomic force microscopy. Their room temperature bondability was investigated using the contact wave velocity and the surface energy of the formed bond as parameters. Different wet cleaning procedures were used to modify the micro-roughness of the silicon surface. It is found that the surface rms roughness value is not a good measure for judging the bondability of a surface. Instead we propose the use of the Fourier spectrum of the surface roughness. The occurrence of low, ~0.001 Å-1, spatial frequency components of large amplitude in the Fourier spectrum of the surface roughness may affect the bondability of the surface negatively while higher frequency components are not as important
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| 8. |
- Bengtsson, Stefan, 1961, et al.
(author)
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Silicon on aluminum nitride structures formed by wafer bonding
- 1994
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In: 1994 IEEE International SOI Conference Proceedings. ; , s. 35-
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Journal article (peer-reviewed)abstract
- This paper deals with the use of reactively sputtered aluminum nitride (AlN) films as insulators for Bond and Etch-back Silicon-On-Insulator (BESOI) materials. In SOI-applications where high power is dissipated in the silicon SOI-film the low thermal conductivity of the buried silicon dioxide layer may cause a temperature rise in the silicon film detrimentally affecting the device performance. An attractive alternative would be to replace the silicon dioxide of the SOI structure with another material, like diamond, silicon carbide or aluminum nitride. The thermal conductivity of AlN is considerably larger than that of Si02. This paper presents results on how sputter deposition of AlN may be combined with wafer bonding for the creation of highly thermally conductive SOI structures
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| 10. |
- Bergh, Mats, 1968
(author)
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Wafer Bonding - Problems and Possibilities
- 1998
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Doctoral thesis (other academic/artistic)abstract
- The wafer bonding technology offers a unique opportunity to combine different materials. This has been used for the realisation of novel silicon on insulator (SOI) structures. By replacing the buried silicon dioxide layer with a polycrystalline diamond film the thermal properties of the SOI structure are improved. Also experiments using aluminium nitride film as the buried insulator are presented. It is also showed that wafer bonding can be used for the formation of a semi-insulating substrate. Since wafer bonding is adhesion between surfaces, specific surface requirements for successful bonding have been investigated. Surface roughness and chemical termination are key issues for successful bonding. Various methods for measuring the surface roughness are discussed. Focus has been held at Atomic Force Microscope (AFM) for determining the surface roughness. The influence of the measuring technique on the result has been investigated. It is found essential to determine the smallest unique dominating surface feature, which sets the scale for measuring the surface roughness for every material. Then the surface roughness can be related to the bondability of the materials. The use of wafer bonding in other applications like in micro-mechanics or for bonding III-V materials are also discussed. Some examples of what have been done are given. Finally a few reflections about the future are made.
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