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Advanced Detectors, Systems, & Nanoscience

JPL/Alacron Inc.’s high-speed 3-megapixel superlattice-doped CMOS camera.

MDL Superlattice-Doped Detectors Provide Unprecedented Stability and Performance

Despite over 40 years of development, backside-illuminated detectors are not sufficiently stable for many applications. MDL has developed superlattice-doped detectors with exceptional stability and quantum efficiency (QE) in the deep and far-UV. Superlattice doping represents a fundamentally different approach to surface passivation than conventional methods of ion implantation and diffusion. The structure of the superlattice comprises multiple layers of delta-doped silicon grown by molecular-beam epitaxy. Its stability enables nearly 100% charge collection efficiency independent of the density of interface traps.

MDL recently partnered with Alacron, Inc. to develop a high-speed imaging camera in which superlattice-doped CMOS imaging detectors provide the essential stability and sensitivity for deep ultraviolet (DUV) lithography applications in the semiconductor industry. The detectors achieve nearly 100% internal QE in the deep and far-UV with a 64% external QE at 263 nm. In lifetime tests performed at Applied Materials, the QE and dark current of the camera remained stable to better than 1% precision during long-term exposure to several billion laser pulses, with no measurable degradation, no blooming, and no image memory at 1000 fps.

Superlattice-doped, antireflection-coated CMOS imaging array.

MDL is now working with industry and university partners on further development and applications of superlattice-doping technology for DUV lithography, electron microscopy, and high-sensitivity photon and particle detection.

 

Current Projects