| 1. |
- Bengtsson, Stefan, 1961, et al.
(författare)
-
Integration of silicon and diamond, aluminum nitride or aluminum oxide for electronic materials
- 1999
-
Ingår i: conference proceedings:III-V and IV-IV Materials and Processing Challenges for Highly Integrated Microelectronics and Optoelectronics. Symposium.. ; , s. 133-
-
Konferensbidrag (refereegranskat)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
|
|
| 2. |
- Bengtsson, Jörgen, 1968
(författare)
-
Diffractive Optics Design
- 1997
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Diffractive optical elements (kinoforms) change the way light propagates, and can perform very complex tasks. They can split an incident beam into any number of outgoing, and possibly focused, beams (fan-out). Other kinoforms shape the cross sectional intensity distribution of the beam, which is often Gaussian, into a rectangle with constant intensity, for instance. What function the kinoform implements depends on the surface relief etched on the kinoform. This work considers important aspects of the design of diffractive optical elements, within the scalar optics approximation, such as - efficient optimization of the kinoform relief with the optimal-rotation-angle method. For example, shallow, phase-swing restricted kinoforms are designed. - non-diffraction-limited (beam shaping) design. One experimental example is a semiconductor laser beam shaping system consisting only of a multiple-function kinoform. - finding a model for the effects of fabrication on the relief (the proximity effect) and trying to compensate for this effect already in the design, which can yield very uniform fan-out patterns even when the proximity effect is considerable. - integrating diffractive optics with semiconductor optics. Examples are kinoforms illuminated by VCSELs and dislocated binary gratings that outcouple a guided wave and also impose a continuous phase modulation on the outcoupled wave. - using the exact (no Fresnel approximation, for instance) scalar theory, based on the scalar wave (Helmholtz) equation, in an efficient formulation that enables the design of kinoforms producing virtually any desired, three-dimensional, fan-out light distribution.
|
|
