Raytheon Company

Santa Barbara Research Center

Scott M Johnson

Terence J De Lyon

William L Ahlgren

William J Hamilton, Jr

Justin G A Wehner

A broadband radiation detector includes a first layer having a first type of electrical conductivity type. A second layer has a second type of electrical conductivity type and an energy bandgap responsive to radiation in a first spectral region. A third layer has the second type of electrical conductivity type and an energy bandgap responsive to radiation in a second spectral region comprising longer wavelengths than the wavelengths of the first spectral region. The broadband radiation detector further includes a plurality of internal regions. Each internal region may be disposed at least partially within the third layer and each internal region may include a refractive index that is different from a refractive index of the third layer. The plurality of internal regions may be arranged according to a regularly repeating pattern.

Multi-band, reduced-volume radiation detectors and methods of formation

A method is provided for depositing a (111)-oriented heteroepitaxial II-VI alloy film on Si substrates. The (111)-oriented heteroepitaxial II-VI alloy film may comprise II-VI semiconductor and/or II-VI semimetal. As such, the method of the present invention provides a means for growing a (111)-oriented heteroepitaxial II-VI semiconductor film or a (111)-oriented heteroepitaxial II-VI semimetal film. The method of the present invention overcomes the inherent difficulties associated with forming (111)-oriented heteroepitaxial II-VI alloy films on Si(001). These difficulties include twin formation and poor crystalline quality. The novelty of the method of the present invention consists principally in choosing a Si substrate having a surface which has a specific Si crystallographic orientation. In particular, the present invention utilizes a Si surface having a crystallographic orientation near Si(111) rather than Si(001). The Si surface is vicinal Si(111). The angle of the misorientation of the Si surface from the Si(111) plane can range from 2.degree. to 8.degree..

Method for epitaxial growth of twin-free, (111)-oriented II-VI alloy

A layer (32) of a HgCdTe compound epitaxially contacts a buffer structure, which in turn epitaxially contacts a silicon substrate (22). The buffer structure is formed of II-VI compounds, and preferably includes at least one layer (24) of a ZnSeTe compound epitaxially contacting the silicon substrate (22) and a layer (30) of a CdZnTe compound overlying the ZnSeTe compound layer (24). The ZnSeTe compound layer (24) may be provided as a single graded layer having a composition of ZnSe adjacent to the silicon and a composition of ZnTe remote from the silicon, or as two distinct sublayers with a ZnSe sublayer (26) adjacent to the silicon substrate (22) and a ZnTe sublayer (28) remote from the silicon substrate (22).

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Santa Barbara, CA, United States of America

Scott M Johnson