64
nanotimes News in Brief
11-05 :: May/June 2011
Production Systems // Solution for the Production of Long-range Infrared Microsensors
R
esearchers of the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in
Duisburg, Germany, are now offering a solution for the production of long-range infrared microsen- sors. On June 22, they will be opening a new facility in which the production of such micro-system tech- nology (MST) is possible. MST involves minute sen- sors, valves or other mechanical components that are integrated into semiconductor chips. For instance, in airbags they serve as motion sensors, and they are no thicker than a human hair. If MST is to be applied on semiconductors and integrated, one has to master the art of etching – which is where the researchers at IMS come in.
“Traditional etching methods allow us only to etch vertically into the layers,“ explains Dr. Marco Russ, project manager at IMS. “However, unsupported structures are decisive for the mechanical functions of many items of MST.“ In other words: the etching must work not only vertically but evenly in all direc- tions. Experts call this process “isotropic etching.“
This ensures that the etching substance not only eats vertically to the substrate but also digs itself under the function layer, like a tunnel. What remains is an unsupported structure of the function layer that is only one hundred nanometers thin and connected
to the substrate only at certain suspension points. “A conventional technique is etching with liquids“, says Russ. However, capillary forces can occur when the etching fluid dries. The result: the filigree membra- nes are glued to the substrate or are even destroyed. In addition, most etching liquids do not permit the choice of just any combination of materials for the function and sacrificial layers.
“We bypass these problems with our new facility,“ says Russ. The highlight: “We can use two different gases in the processing chambers of the machine instead of fluids.“ They are highly selective: hydrogen fluoride (HF) has strong etching properties on silicon dioxide but does not affect silicon. The exact reverse is the case with xenon difluoride gas (XeF2
).
“This way, we can select which material is better suited to be the function layer,“ says Russ. The new facility could revolutionize MST production, since the process works in a highly precise manner on an industrial scale. And: whether thermal detectors, acceleration sensors and pressure sensors or micro machines – a multitude of MST structures can be produced in this way.
http://www.ims.fraunhofer.de
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95