Senior infrared detector development engineer, with extensive experience with HgCdTe and infrared focal plane array manufacture and performance predictions
SEG Technical Program Expanded Abstracts 1992, 1992
Reverse Vertical Seismic Profiling VSP and interwell seismic experiments were conducted at the We... more Reverse Vertical Seismic Profiling VSP and interwell seismic experiments were conducted at the Western Kentucky Petroleum Buckhorn test site near Quincy, Illinois. The RVSP data were acquired using a 3-component pneumatic probe and the interwell seismic data were acquired using a 24-element hydrophone array. The experiments were conducted to analyze high resolution seismic waveforms and to perform travel time velocity inversion for mapping the Silurian Kankakee formation which is the more prolific oil producer in the Mt. Sterling area. Reverse VSP and interwell seismic measurements together with log data have yielded information on the anisotropic characteristic of the shale formation and in the compressional wave velocity distribution of the limestone formation. These results inferred that reverse VSP (using several 3-component detectors in shallow boreholes) and interwell seismic measurements integrated with log data and seismic modeling can delineate the hydrocarbon reservoir and geological structures at the Buckhorn test site.
*Author to whom all correspondence and reprint requests should be addressed. Current address: De... more *Author to whom all correspondence and reprint requests should be addressed. Current address: Department of Medical Research and Technology, University of Maryland School of Medicine, 100 Penn Street, Baltimore, MD 21201, E-mail: CLouime@ som.umaryland.edu
Since its initial synthesis and investigation more than 40 years ago, the HgCdTe alloy semiconduc... more Since its initial synthesis and investigation more than 40 years ago, the HgCdTe alloy semiconductor system has evolved into one of the primary infrared detector materials for high-performance infrared focal-plane arrays (FPA) designed to operate in the 3-5 mm and 8-12 mm spectral ranges of importance for thermal imaging systems. Over the course of the past decade, significant advances have
High-performance large-format detector arrays responsive to the 1-5mum wavelength range of the in... more High-performance large-format detector arrays responsive to the 1-5mum wavelength range of the infrared spectrum fabricated using large area HgCdTe layers grown on 6-inch diameter (211) silicon substrates are available for advanced imaging applications. This paper reviews performance and capabilities of Raytheon Vision Systems (RVS) HgCdTe/Si Focal Plane Arrays (FPA) and shows 2k x 2k format MWIR HgCdTe/Si FPA performance with
Large format detector arrays are responsive uniformly over spectral 1-5µm wavelength range and ar... more Large format detector arrays are responsive uniformly over spectral 1-5µm wavelength range and are available with RVS' high quality HgCdTe detector epitaxial layers on large area 15 cm diameter wafers. Large wafers enable both low cost High Definition (HD) staring FPAs, as well as the ability to approach giga-pixel format detector arrays with a seamless 10cm ×10cm continuous image plane size possible. With a 15 cm diameter detector substrate it is a straightforward growth path to a 5k×5k µm pitch 25 Mega-pixel infrared focal plane array (FPA) with smaller pitches allowing even greater format along the 10cm die length. This paper describes arrays 1.5 to 4 Mega-pixel infrared HgCdTe developed by RVS for demanding higher performance applications. Performance data for both the detector and ROIC for typical SWIR and MWIR FPAs operating at 85K will be presented. This paper will provide FPA performance capability for small pitch large format HgCdTe/Si detector arrays fabricated at RVS and manufacturing readiness low cost Mega-pixel infrared FPAs for current and future wide FOV high-resolution systems.
SPIE International Symposium on Optical Science and Technology, 2001
Since its initial synthesis and investigation more than 40 years ago, the HgCdTe alloy semiconduc... more Since its initial synthesis and investigation more than 40 years ago, the HgCdTe alloy semiconductor system has evolved into one of the primary infrared detector materials for high-performance infrared focal-plane arrays (FPA) designed to operate in the 3-5 µm and 8-12 µm spectral ranges of importance for thermal imaging systems. Over the course of the past decade, significant advances have been made in the development of thin-film epitaxial growth techniques, such as molecular-beam epitaxy (MBE), which have enabled the synthesis of IR detector device structures with complex doping and composition profiles. The central role played by in situ sensors for monitoring and control of the MBE growth process are reviewed. The development of MBE HgCdTe growth technology is discussed in three particular device applications: avalanche photodiodes for 1.55 µm photodetection, megapixel FPAs on Si substrates, and multispectral IR detectors.
Raytheon Vision Systems (RVS) is producing large format, high definition HgCdTe-based MWIR and SW... more Raytheon Vision Systems (RVS) is producing large format, high definition HgCdTe-based MWIR and SWIR focal plane arrays (FPAs) with pitches of 15 µm and smaller for various applications. Infrared sensors fabricated from HgCdTe have several advantages when compared to those fabricated from other materials-such as a highly tunable bandgap, high quantum efficiencies, and R 0 A approaching theoretical limits. It is desirable to operate infrared sensors at elevated operating temperatures in order to increase the cooler life and reduce the required system power. However, the sensitivity of many infrared sensors, including those made from HgCdTe, declines significantly above a certain temperature due to the noise resulting from increasing detector dark current. In this paper we provide performance data on a MWIR and a SWIR focal plane array operating at temperatures up to 160K and 170K, respectively. The FPAs used in the study were grown by molecular beam epitaxy (MBE) on silicon substrates, processed into a 1536x1024 format with a 15 µm pixel pitch, and hybridized to a silicon readout integrated circuit (ROIC) via indium bumps to form a sensor chip assembly (SCA). This data shows that the noise equivalent delta temperature (NEDT) is background limited at f/3.4 in the SWIR SCA (cutoff wavelength of 3.7 µm at 130K) up to 140K and in the MWIR SCA (cutoff wavelength of 4.8 µm at 115K) up to 115K.
This paper presents the infrared detector performance improvement accomplishments by Raytheon Vis... more This paper presents the infrared detector performance improvement accomplishments by Raytheon Vision Systems (RVS) and by AVYD Devices Inc (AVYD). The RVS-AVYD collaboration has resulted in the demonstration of very large imaging focal plane arrays with respectable operability and performance which could potentially be useful in a variety of promising new applications to advance performance capability for future near and short wave infrared imaging missions. This detector design concept potentially permits ultra-small pixel large format imaging capabilities for diffraction limited resolution down to 5µm pitch focal planes. In this paper, we report on the work performed at the RVS's advanced prototype engineering facility, to fabricate planar detector array wafers with a combination of RVS's Hg 1-x Cd x Te production material growth and detector fabrication processes and AVYD's p-type ion-implantation process. This paper will review the performance of a 20µm pitch 1,024 X 1,024 format SWIR focal plane array. The detector array was fabricated in Hg 1-x Cd x Te material responsive from near-infrared to 2.5µm cutoff wavelength. Imaging capability was achieved via interconnect bump bond connection of this detector array to an RVS astronomy grade readout chip. These focal plane arrays have exhibited outstanding quantum efficiency uniformity and magnitude over the entire spectral range and in addition, have also exhibited very low leakage current with median values of 0.25 electrons per second. Detector arrays were processed in engineering grade Hg 1-x Cd x Te epitaxial layers grown with a modified liquid phase epitaxy process on CdZnTe substrates followed by a combination of passivation/ion implantation/passivation steps. This paper will review the detector performance data in detail including the test structure current-voltage plots, spectral cutoff curves, FPA quantum efficiency, and leakage current.
Dark current density data recorded over the past 14 years at Raytheon Vision Systems on short-wav... more Dark current density data recorded over the past 14 years at Raytheon Vision Systems on short-wavelength infrared (SWIR) and medium-wavelength infrared (MWIR) devices were examined. This included HgCdTe detector arrays grown by liquid-phase epitaxy on CdZnTe and molecular beam epitaxy on both silicon and CdZnTe substrates. This study analyzed zero-bias resistance-area product and current-voltage measurements from test structure assemblies included on every detector wafer. The data span cutoff wavelengths from 1.7 lm to 7.5 lm and operating temperatures from 40 K to 300 K. A basis is derived for a simple manufacturing trend model for a wide range of cutoffs and temperatures. This model uses a function similar to Tennant's Rule'07 but includes a generation-recombination (GR) term. Dark current densities below the test set limit are extrapolated assuming GR-limited performance. Model assumptions are tested using sensor chip assembly (SCA) median dark current density values at the same inverse cutoff-temperature products. This model allows probabilistic determination of array manufacturability and prediction of yield, and provides a statistical basis for Raytheon's state-of-the-art performance.
Proceeding of SPIE 8012, Infrared Technology and Applications XXXVII, 2011
High-performance large-format detector arrays responsive to the 1-5µm wavelength range of the inf... more High-performance large-format detector arrays responsive to the 1-5µm wavelength range of the infrared spectrum fabricated using large area HgCdTe layers grown on 6-inch diameter (211) silicon substrates are available for advanced imaging applications. This paper reviews performance and capabilities of Raytheon Vision Systems (RVS) HgCdTe/Si Focal Plane Arrays (FPA) and shows 2k x 2k format MWIR HgCdTe/Si FPA performance with NEdT operabilities better than 99.9%. SWIR and MWIR detector performance for HgCdTe/Si is comparable to established performance of HgCdTe/CdZnTe wafers. HgCdTe devices fabricated on both types of substrates have demonstrated very low dark current, high quantum efficiency and full spectral band fill factor characteristic of HgCdTe. HgCdTe has the advantage of being able to precisely tune the detector cutoff via adjustment of the Cd composition in the MBE growth. The HgCdTe/Si detectors described in this paper are p-on-n mesa delineated architecture and fabricated using the same mature etch, passivation, and metallization processes as our HgCdTe/CdZnTe line. Uniform device quality HgCdTe epitaxial layers and application of detector fabrication processes across the full area of 6-inch wafers routinely produces high performing detector pixels from edge to edge of the photolithographic limits across the wafer, offering 5 times the printable area as costly 6×6cm CdZnTe substrates. This 6-inch HgCdTe detector wafer technology can provide applications demanding very wide FOV high resolution coverage the capability to produce a very large single piece infrared detector array, up to a continuous image plane 10×10 cm in size. Alternatively, significant detector cost reduction through allowing more die of a given size to be printed on each wafer is possible, with further cost reduction achieved through transition towards automated detector fabrication and photolithographic processes for both increased yields and reduced touch labor costs. RVS continues to improve its FPA manufacturing line towards achieving low cost infrared FPAs with the format, size, affordability, and performance required for current and future infrared applications.
This paper presents the status of HgCdTe growth on large-area Si and CdZnTe substrates at Raytheo... more This paper presents the status of HgCdTe growth on large-area Si and CdZnTe substrates at Raytheon Vision Systems (RVS). The different technological tools that were used to scale up the growth from 4 inch to 6 inch diameter on Si and from 4 cm 9 4 cm to 8 cm 9 8 cm on CdZnTe without sacrificing the quality of the layers are described. Extremely high compositional uniformity and low macrodefect density were achieved for single-and two-color HgCdTe layers on both Si and CdZnTe substrates. Finally, a few examples of detector and focal-plane array results are included to highlight the importance of high compositional uniformity and uniformly low macrodefect density of the epitaxial layers in obtaining high operability and low cluster outages in single-and two-color focal-plane arrays (FPAs).
SEG Technical Program Expanded Abstracts 1992, 1992
Reverse Vertical Seismic Profiling VSP and interwell seismic experiments were conducted at the We... more Reverse Vertical Seismic Profiling VSP and interwell seismic experiments were conducted at the Western Kentucky Petroleum Buckhorn test site near Quincy, Illinois. The RVSP data were acquired using a 3-component pneumatic probe and the interwell seismic data were acquired using a 24-element hydrophone array. The experiments were conducted to analyze high resolution seismic waveforms and to perform travel time velocity inversion for mapping the Silurian Kankakee formation which is the more prolific oil producer in the Mt. Sterling area. Reverse VSP and interwell seismic measurements together with log data have yielded information on the anisotropic characteristic of the shale formation and in the compressional wave velocity distribution of the limestone formation. These results inferred that reverse VSP (using several 3-component detectors in shallow boreholes) and interwell seismic measurements integrated with log data and seismic modeling can delineate the hydrocarbon reservoir and geological structures at the Buckhorn test site.
*Author to whom all correspondence and reprint requests should be addressed. Current address: De... more *Author to whom all correspondence and reprint requests should be addressed. Current address: Department of Medical Research and Technology, University of Maryland School of Medicine, 100 Penn Street, Baltimore, MD 21201, E-mail: CLouime@ som.umaryland.edu
Since its initial synthesis and investigation more than 40 years ago, the HgCdTe alloy semiconduc... more Since its initial synthesis and investigation more than 40 years ago, the HgCdTe alloy semiconductor system has evolved into one of the primary infrared detector materials for high-performance infrared focal-plane arrays (FPA) designed to operate in the 3-5 mm and 8-12 mm spectral ranges of importance for thermal imaging systems. Over the course of the past decade, significant advances have
High-performance large-format detector arrays responsive to the 1-5mum wavelength range of the in... more High-performance large-format detector arrays responsive to the 1-5mum wavelength range of the infrared spectrum fabricated using large area HgCdTe layers grown on 6-inch diameter (211) silicon substrates are available for advanced imaging applications. This paper reviews performance and capabilities of Raytheon Vision Systems (RVS) HgCdTe/Si Focal Plane Arrays (FPA) and shows 2k x 2k format MWIR HgCdTe/Si FPA performance with
Large format detector arrays are responsive uniformly over spectral 1-5µm wavelength range and ar... more Large format detector arrays are responsive uniformly over spectral 1-5µm wavelength range and are available with RVS' high quality HgCdTe detector epitaxial layers on large area 15 cm diameter wafers. Large wafers enable both low cost High Definition (HD) staring FPAs, as well as the ability to approach giga-pixel format detector arrays with a seamless 10cm ×10cm continuous image plane size possible. With a 15 cm diameter detector substrate it is a straightforward growth path to a 5k×5k µm pitch 25 Mega-pixel infrared focal plane array (FPA) with smaller pitches allowing even greater format along the 10cm die length. This paper describes arrays 1.5 to 4 Mega-pixel infrared HgCdTe developed by RVS for demanding higher performance applications. Performance data for both the detector and ROIC for typical SWIR and MWIR FPAs operating at 85K will be presented. This paper will provide FPA performance capability for small pitch large format HgCdTe/Si detector arrays fabricated at RVS and manufacturing readiness low cost Mega-pixel infrared FPAs for current and future wide FOV high-resolution systems.
SPIE International Symposium on Optical Science and Technology, 2001
Since its initial synthesis and investigation more than 40 years ago, the HgCdTe alloy semiconduc... more Since its initial synthesis and investigation more than 40 years ago, the HgCdTe alloy semiconductor system has evolved into one of the primary infrared detector materials for high-performance infrared focal-plane arrays (FPA) designed to operate in the 3-5 µm and 8-12 µm spectral ranges of importance for thermal imaging systems. Over the course of the past decade, significant advances have been made in the development of thin-film epitaxial growth techniques, such as molecular-beam epitaxy (MBE), which have enabled the synthesis of IR detector device structures with complex doping and composition profiles. The central role played by in situ sensors for monitoring and control of the MBE growth process are reviewed. The development of MBE HgCdTe growth technology is discussed in three particular device applications: avalanche photodiodes for 1.55 µm photodetection, megapixel FPAs on Si substrates, and multispectral IR detectors.
Raytheon Vision Systems (RVS) is producing large format, high definition HgCdTe-based MWIR and SW... more Raytheon Vision Systems (RVS) is producing large format, high definition HgCdTe-based MWIR and SWIR focal plane arrays (FPAs) with pitches of 15 µm and smaller for various applications. Infrared sensors fabricated from HgCdTe have several advantages when compared to those fabricated from other materials-such as a highly tunable bandgap, high quantum efficiencies, and R 0 A approaching theoretical limits. It is desirable to operate infrared sensors at elevated operating temperatures in order to increase the cooler life and reduce the required system power. However, the sensitivity of many infrared sensors, including those made from HgCdTe, declines significantly above a certain temperature due to the noise resulting from increasing detector dark current. In this paper we provide performance data on a MWIR and a SWIR focal plane array operating at temperatures up to 160K and 170K, respectively. The FPAs used in the study were grown by molecular beam epitaxy (MBE) on silicon substrates, processed into a 1536x1024 format with a 15 µm pixel pitch, and hybridized to a silicon readout integrated circuit (ROIC) via indium bumps to form a sensor chip assembly (SCA). This data shows that the noise equivalent delta temperature (NEDT) is background limited at f/3.4 in the SWIR SCA (cutoff wavelength of 3.7 µm at 130K) up to 140K and in the MWIR SCA (cutoff wavelength of 4.8 µm at 115K) up to 115K.
This paper presents the infrared detector performance improvement accomplishments by Raytheon Vis... more This paper presents the infrared detector performance improvement accomplishments by Raytheon Vision Systems (RVS) and by AVYD Devices Inc (AVYD). The RVS-AVYD collaboration has resulted in the demonstration of very large imaging focal plane arrays with respectable operability and performance which could potentially be useful in a variety of promising new applications to advance performance capability for future near and short wave infrared imaging missions. This detector design concept potentially permits ultra-small pixel large format imaging capabilities for diffraction limited resolution down to 5µm pitch focal planes. In this paper, we report on the work performed at the RVS's advanced prototype engineering facility, to fabricate planar detector array wafers with a combination of RVS's Hg 1-x Cd x Te production material growth and detector fabrication processes and AVYD's p-type ion-implantation process. This paper will review the performance of a 20µm pitch 1,024 X 1,024 format SWIR focal plane array. The detector array was fabricated in Hg 1-x Cd x Te material responsive from near-infrared to 2.5µm cutoff wavelength. Imaging capability was achieved via interconnect bump bond connection of this detector array to an RVS astronomy grade readout chip. These focal plane arrays have exhibited outstanding quantum efficiency uniformity and magnitude over the entire spectral range and in addition, have also exhibited very low leakage current with median values of 0.25 electrons per second. Detector arrays were processed in engineering grade Hg 1-x Cd x Te epitaxial layers grown with a modified liquid phase epitaxy process on CdZnTe substrates followed by a combination of passivation/ion implantation/passivation steps. This paper will review the detector performance data in detail including the test structure current-voltage plots, spectral cutoff curves, FPA quantum efficiency, and leakage current.
Dark current density data recorded over the past 14 years at Raytheon Vision Systems on short-wav... more Dark current density data recorded over the past 14 years at Raytheon Vision Systems on short-wavelength infrared (SWIR) and medium-wavelength infrared (MWIR) devices were examined. This included HgCdTe detector arrays grown by liquid-phase epitaxy on CdZnTe and molecular beam epitaxy on both silicon and CdZnTe substrates. This study analyzed zero-bias resistance-area product and current-voltage measurements from test structure assemblies included on every detector wafer. The data span cutoff wavelengths from 1.7 lm to 7.5 lm and operating temperatures from 40 K to 300 K. A basis is derived for a simple manufacturing trend model for a wide range of cutoffs and temperatures. This model uses a function similar to Tennant's Rule'07 but includes a generation-recombination (GR) term. Dark current densities below the test set limit are extrapolated assuming GR-limited performance. Model assumptions are tested using sensor chip assembly (SCA) median dark current density values at the same inverse cutoff-temperature products. This model allows probabilistic determination of array manufacturability and prediction of yield, and provides a statistical basis for Raytheon's state-of-the-art performance.
Proceeding of SPIE 8012, Infrared Technology and Applications XXXVII, 2011
High-performance large-format detector arrays responsive to the 1-5µm wavelength range of the inf... more High-performance large-format detector arrays responsive to the 1-5µm wavelength range of the infrared spectrum fabricated using large area HgCdTe layers grown on 6-inch diameter (211) silicon substrates are available for advanced imaging applications. This paper reviews performance and capabilities of Raytheon Vision Systems (RVS) HgCdTe/Si Focal Plane Arrays (FPA) and shows 2k x 2k format MWIR HgCdTe/Si FPA performance with NEdT operabilities better than 99.9%. SWIR and MWIR detector performance for HgCdTe/Si is comparable to established performance of HgCdTe/CdZnTe wafers. HgCdTe devices fabricated on both types of substrates have demonstrated very low dark current, high quantum efficiency and full spectral band fill factor characteristic of HgCdTe. HgCdTe has the advantage of being able to precisely tune the detector cutoff via adjustment of the Cd composition in the MBE growth. The HgCdTe/Si detectors described in this paper are p-on-n mesa delineated architecture and fabricated using the same mature etch, passivation, and metallization processes as our HgCdTe/CdZnTe line. Uniform device quality HgCdTe epitaxial layers and application of detector fabrication processes across the full area of 6-inch wafers routinely produces high performing detector pixels from edge to edge of the photolithographic limits across the wafer, offering 5 times the printable area as costly 6×6cm CdZnTe substrates. This 6-inch HgCdTe detector wafer technology can provide applications demanding very wide FOV high resolution coverage the capability to produce a very large single piece infrared detector array, up to a continuous image plane 10×10 cm in size. Alternatively, significant detector cost reduction through allowing more die of a given size to be printed on each wafer is possible, with further cost reduction achieved through transition towards automated detector fabrication and photolithographic processes for both increased yields and reduced touch labor costs. RVS continues to improve its FPA manufacturing line towards achieving low cost infrared FPAs with the format, size, affordability, and performance required for current and future infrared applications.
This paper presents the status of HgCdTe growth on large-area Si and CdZnTe substrates at Raytheo... more This paper presents the status of HgCdTe growth on large-area Si and CdZnTe substrates at Raytheon Vision Systems (RVS). The different technological tools that were used to scale up the growth from 4 inch to 6 inch diameter on Si and from 4 cm 9 4 cm to 8 cm 9 8 cm on CdZnTe without sacrificing the quality of the layers are described. Extremely high compositional uniformity and low macrodefect density were achieved for single-and two-color HgCdTe layers on both Si and CdZnTe substrates. Finally, a few examples of detector and focal-plane array results are included to highlight the importance of high compositional uniformity and uniformly low macrodefect density of the epitaxial layers in obtaining high operability and low cluster outages in single-and two-color focal-plane arrays (FPAs).
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Papers by Jim Bangs