Teknologian Tutkimuskeskus Vtt Oy

Bin Guo

Heikki Saari

Aapo Varpula

Anna Rissanen

A wafer-level integrated thermal detector comprises a first wafer and a second wafer (W, W) bonded together. The first wafer (W) includes a dielectric or semiconducting substrate (), a dielectric sacrificial layer () deposited on the substrate, a support layer () deposited on the sacrificial layer or the substrate, a suspended active element () provided within an opening () in the support layer, a first vacuum-sealed cavity () and a second vacuum-sealed cavity () on opposite sides of the suspended active element. The first vacuum-sealed cavity () extends into the sacrificial layer () at the location of the suspended active element (). The second vacuum-sealed cavity () comprises the opening of the support layer () closed by the bonded second wafer. The thermal detector further comprises front optics () for entrance of radiation from outside into one of the first and second vacuum-sealed cavities, aback reflector () arranged to reflect radiation back into the other one of the first and second vacuum-sealed cavities, and electrical connections () for connecting the suspended active element to a readout circuit ().

Thermal detector and thermal detector array

A microelectromechanical (MEMS) Fabry-Perot interferometer includes a transparent substrate; a first metallic mirror structure on the transparent substrate, including a first metal layer and a first support layer; a second metallic mirror structure above the first metallic mirror structure on an opposite side of the first metallic mirror structure in view of the transparent substrate, the second metallic mirror structure including a second metal layer and a second support layer, wherein the first and the second support layer are parallel and including at least one of aluminum oxide or titanium dioxide; a Fabry-Perot cavity between the first and the second support layer, whereby the Fabry-Perot cavity is formed by providing an insulation layer on the first mirror structure, and at least partially removing the insulation layer after providing the second mirror structure; and electrodes for providing electrical contacts to the first and the second metal layer.

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Vtt, Finland

Bin Guo