The United States of America As Represented by the Administrator of the

Eric W Jones

Robert W Fathauer

Thomas George

Sarath D Gunapala

True-Lon Lin

Thierry F Caillat

Jin S Park

Marc C Foote

Hector M Del Castillo

Golf putter head

Linear arrays with up to 63 micromachined thermopile infrared detectors on silicon substrates have been constructed and tested. Each detector consists of a suspended silicon nitride membrane with 11 thermocouples of sputtered Bi--Te and Bi--Sb--Te thermoelectric elements films. At room temperature and under vacuum these detectors exhibit response times of 99 ms, zero frequency D* values of 1.4.times.10.sup.9 cmHz.sup.1/2 /W and responsivity values of 1100 V/W when viewing a 1000 K blackbody source. The only measured source of noise above 20 mHz is Johnson noise from the detector resistance. These results represent the best performance reported to date for an array of thermopile detectors. The arrays are well suited for uncooled dispersive point spectrometers. In another embodiment, also with Bi--Te and Bi--Sb--Te thermoelectric materials on micromachined silicon nitride membranes, detector arrays have been produced with D* values as high as 2.2.times.10.sup.9 cmHz.sup.1/2 /W for 83 ms response times.

Micromachined thermoelectric sensors and arrays and process for producing

Monocrystalline semiconductor lattices with a buried porous semiconductor layer having different chemical composition. Also monocrystalline semiconductor superlattices with a buried porous semiconductor layers having different chemical composition than that of its monocrystalline semiconductor superlattice. Lattices of alternating layers of monocrystalline silicon and porous silicon-germanium have been produced. These single crystal lattices have been fabricated by epitaxial growth of Si and Si-Ge layers followed by patterning into mesa structures. The mesa structures are stain etched resulting in porosification of the Si-Ge layers with a minor amount of porosification of the monocrystalline Si layers. Thicker Si-Ge layers produced in a similar manner emitted visible light at room temperature.

Buried porous silicon-germanium layers in monocrystalline silicon

Lattices of alternating layers of monocrystalline silicon and porous silicon-germanium have been produced. These single crystal lattices have been fabricated by epitaxial growth of Si and Si--Ge layers followed by patterning into mesa structures. The mesa structures are stain etched resulting in porosification of the Si--Ge layers with a minor amount of porosification of the monocrystalline Si layers. Thicker Si--Ge layers produced in a similar manner emitted visible light at room temperature.

Method of producing buried porous silicon-geramanium layers in

Extended cutoff wavelengths of PtSi Schottky infrared detectors in the long wavelength infrared (LWIR) regime have been demonstrated for the first time. This result was achieved by incorporating a 1-nm-thick p+ doping spike at the PtSi/Si interface. The extended cutoff wavelengths resulted from the combined effects of an increased electric field near the silicide/Si interface due to the p+ doping spike and the Schottky image force. The p+ doping spikes were grown by molecular beam epitaxy at 450 degrees Celsius using elemental boron as the dopant source, with doping concentrations ranging from 1.times.10.sup.19 to 1.times.10.sup.21 cm.sup.-3. The cutoff wavelengths were shown to increase with increasing doping concentrations of the p+ spikes.

Long-wavelength PTSI infrared detectors and method of fabrication thereof

A pattern of porous silicon is produced in the surface of a silicon substrate by forming a pattern of crystal defects in said surface, preferably by applying an ion milling beam through openings in a photoresist layer to the surface, and then exposing said surface to a stain etchant, such as HF:HNO.sub.3 :H.sub.2 O. The defected crystal will preferentially etch to form a pattern of porous silicon. When the amorphous content of the porous silicon exceeds 70% the porous silicon pattern emits visible light at room temperature.

Growing community of inventors

Los Angeles, CA, United States of America

Eric W Jones