Thermal stress accumulated in InSb infrared focal plane arrays (IRFPAs) during liquid nitrogen sh... more Thermal stress accumulated in InSb infrared focal plane arrays (IRFPAs) during liquid nitrogen shock tests usually gives rise to brittle fracture of InSb chips, local delamination between InSb chips and underfill. Upon the specific structure of the InSb IRFPAs installed in the Dewar, we propose the end surface circular ring fixed mode should be adopted to describe its boundary conditions instead of the well-accepted bottom surface center point fixed mode. From the created structure modeling of the InSb IRFPAs adopting the fixing modes mentioned above, we extract the thermal stresses and plot them together for easy comparison. We find that the end surface circular ring fixed mode is superior to the wellaccepted bottom surface center point fixed mode in aspects of the considerable reduction of the thermal stress in the InSb chips, the moderate decrease of both the shear stress and the peeling off stress between the InSb chips and the underfill. All these findings suggest that the thermal stress of the InSb IRFPAs assembled in the Dewar is overestimated by the well-accepted bottom surface center point fixed mode and can be greatly decreased by adjusting its fixing mode.
Three-dimensional equivalent modeling of InSb IRFPAs is created in this paper. Z-components of st... more Three-dimensional equivalent modeling of InSb IRFPAs is created in this paper. Z-components of strain are employed to display deformation distribution characteristics. Design rule of indium bump is proposed, that is, the diameter of indium bump is not larger than 0.4 times element pitch. Design rule of indium bump is verified by series IRFPAs with different formats.
AOPC 2015: Optical Design and Manufacturing Technologies, 2015
One of the major challenges of InAs/GaSb superlattice devices arises owing to the large number of... more One of the major challenges of InAs/GaSb superlattice devices arises owing to the large number of surface states generated during fabrication processes. Surface passivation and subsequent capping of the surfaces are essential for any practical applicability of this material system. In this paper, we passivated InAs/GaSb superlattice infrared detectors proposed anodic fluoride passivation method. Short and mid wavelength InAs/GaSb superlattice infrared materials were grown by Molecular Beam Epitaxy (MBE) on GaSb (100) substrates. A GaSb buffer layer was grown for optimized superlattice growth condition, which can decrease the occurrence of defects with similar pyramidal structure. The result of auger electron spectroscopy (AES) surface scans after anodic fluoride passivation confirms that anodic fluoride passivation treatment did affect. The leakage current as a function of bias voltage (I-V) for InAs/GaSb superlattice infrared detectors has been examined at 77K. Compared with the unpassivated approach, this passivation methods decrease the dark current by approximately five orders of magnitude.
2012 12th International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD), 2012
The quantum efficiency (QE) for mid-wavelength InSb infrared focal plane arrays has been numerica... more The quantum efficiency (QE) for mid-wavelength InSb infrared focal plane arrays has been numerically studied. Effects of the absorption length and thickness of p-region on device QE have been investigated. Our work shows that the optimum thickness of p-region is largely dependent on the absorption characteristics of the InSb.
Abstract Photodiodes of InSb were fabricated on an epitaxial layer grown using molecular beam epi... more Abstract Photodiodes of InSb were fabricated on an epitaxial layer grown using molecular beam epitaxy (MBE). Thermal cleaning of the InSb (0 0 1) substrate surface, 2° towards the (1 1 1) B plane, was performed to remove the oxide. Photodiode properties of МВЕ-formed epitaxial InSb were demonstrated. Zero-bias resistance area product ( R 0 A ) measurements were taken at 80 K under room temperature background for a pixel size of 100 μm × 100 μm. Values were as high as 4.36 × 10 4 Ω/cm 2 , and the average value of R 0 A was 1.66 × 10 4 Ω/cm 2 . The peak response was 2.44 (A/W). The epitaxial InSb photodiodes were fabricated using the same process as bulk crystal InSb diodes with the exception of the junction formation method. These values are comparable to the properties of bulk crystal InSb photodiodes.
An infrared (IR) dual band multi-element detector with the abilities of dual band IR countercount... more An infrared (IR) dual band multi-element detector with the abilities of dual band IR countercountermeasure (IRCCM) and spatial filtering is presented for effective target detection in a complex tactical environment. The detection elements of the detector are specially arranged like a conventional reticle pattern. With special design, the ratio of radiation intensity from two IR bands can be calculated to distinguish the target from the IR target-flare mixed signal and the two detection bands use a common aperture in the seeker. Without a reticle in the optical system of the IR seeker, the dual band detector can still perform spatial filtering to eliminate background noise effectively. The design details of the detector are presented. The performance of the detector's dual band IRCCM and spatial filtering are analyzed. Simulation results are presented verifying validity of the presented method.
The quantum efficiency for mid-wavelength InSb infrared focal plane arrays has been numerically s... more The quantum efficiency for mid-wavelength InSb infrared focal plane arrays has been numerically studied by two dimensional simulators. Effects of thickness of p-type layer on the quantum efficiency under front-side illumination have been obtained. The calculated results can be used to extract the optimal thickness of the p-type layer for different absorption and diffusion lengths. It is indicated that the optimal thickness of the p-type layer strongly depends on the absorption coefficient and the minority carrier lifetimes. The empirical formulas are also obtained to describe the correlation between the optimal thickness of the p-type layer, and the absorption and diffusion lengths.
Indium bumps are generally accepted to possess functions of electrical connection, mechanical sup... more Indium bumps are generally accepted to possess functions of electrical connection, mechanical support and heat transfer in flip-chip devices. After comparing the distribution of stress components along different paths in InSb infrared focal plane arrays (IRFPAs), we ascertain that local enhancement effects of the stress components are remarkable in regions where the indium bumps are. More specifically, the local enhanced tensile stress in InSb chip connected with the indium bumps can lead to the local fracture of the InSb chip, and the locally enhanced shear and peeling stresses may give rise to the local interfacial delamination between the InSb chip and the indium bumps. These inferences are confirmed by the observed local failure characteristics, such as the distribution of the local delamination, the distribution of the crack widths, and the distribution of the cracks. In addition, the simulated Z-component strain distribution in InSb IRFPAs is also consistent with the backside surface profile of the InAs/GaSb IRFPAs fabricated in America with the identical structure, that is, the InSb chip glued with the indium bumps is concave downward, and the InSb chip glued with the underfill is convex upward. Judging from all these confirmed simulation results, we are confident that the indium bumps play a pivotal role in inducing the local failure of InSb IRFPAs. So the role of the indium bumps in causing the local failure of InSb IRFPAs needs to be supplemented and emphasized to comprehensively evaluate the structural reliability of InSb IRFPAs.
Thermal annealing effect on electrical properties of the Pt/Al0.45Ga0.55N Schottky contacts is in... more Thermal annealing effect on electrical properties of the Pt/Al0.45Ga0.55N Schottky contacts is investigated. The ideality factor, barrier height, and series resistance are obtained from the forward I-V characteristics of the Pt/Al0.45Ga0.55N Schottky contacts. For the Schottky contacts without annealing, the ideality factor decreases from 1.77 to 1.50, and series resistance decreases from 213 Ω to 126 Ω, and the barrier height increases from 1.00 to 1.18 eV with increasing temperature. For the Schottky contacts annealed in nitrogen ambient at 450°C for 1 min, the ideality factor decreases from 2.18 to 1.58, and series resistance decreases from 363 Ω to 207 Ω, and the barrier height increases from 0.77 to 1.04 eV with increasing temperature in a temperature range of 198-298 K. The ideality factor and series resistance of the Schottky contacts with annealing are higher than those without annealing, while the barrier height is lower than that without annealing at various temperatures. Variation of the ideality factor with temperature is good agreement with TFE theory. TFE theory analysis shows that the characteristic energy of 36.0 meV for the Schottky contacts with annealing is greater than 19.3 meV for that without annealing, which should be attributed to much more N vacancy produced at the interface between Pt and Al0.45Ga0.55N as a donor impurity due to annealing.
A novel chip pattern with extinction function in Lead salt detectors is specified. Lead Sulfide (... more A novel chip pattern with extinction function in Lead salt detectors is specified. Lead Sulfide (PbS) polycrystalline film is prepared by Chemical Bath Deposition (CMD) on a transparent substrate, then a special figure and structure is saved by lithography techonology on the substrate. As a quaternion detector chip that made by PbS thin film for example in this paper, whose performance including signal, noise, weak-peaks and the uniformity of the chip are too poor to meet the detecting system at the initial stage of research, and the qualified ratio of chips is only 3% .This paper explains the reason why the performance and qualified ratio of chips were so poor, focuses on a novel chip pattern with extinction which avoided the disadvantages of traditional one. the novel chip pattern has been applied in detectors. The novel chip pattern is prepared with PbS thin film which both “extinction slice” and detector chip are based on a same substrate , which not only had absorbed the jumbled light , improved the uniformity and other performance of photosensitive elements, but also had left out the assembly diffculty and precision demand when a extinction slice assembly in the restricted space of inswept detector chip, omitted the production process of extinction slice and shorten the assembly process of the detectors, and the qualified ratio of chips had been improved from 3% to 98%.
International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Infrared Imaging and Applications, 2009
Au-Al 0.30 Ga 0.70 N Lateral Schottky photodiode was fabricated by an electrical breakdown of a s... more Au-Al 0.30 Ga 0.70 N Lateral Schottky photodiode was fabricated by an electrical breakdown of a single Schottky barrier of metal-semiconductor-metal Au-Al 0.30 Ga 0.70 N film rocking curves are about 523.7 arcsec for the (00.2) plane reflection and about 989.5 arcsec for the ...
This paper gives the example of making infrared wire grid polarizer used in 8 to approximately 14... more This paper gives the example of making infrared wire grid polarizer used in 8 to approximately 14 micrometers wave range by ion beam milling. We have measured and calculated the transmissibility and polarizability of the polarizer. The results have been analyzed and compared with those derived from the theory. it is illustrated that we can get uniform and better quality polarizer by using this method.
2006 8th International Conference on Solid-State and Integrated Circuit Technology Proceedings, 2006
An improved thermally isolated bulk-silicon-micromachined microemitter that can be applied for dy... more An improved thermally isolated bulk-silicon-micromachined microemitter that can be applied for dynamic infrared scene projectors has been fabricated using commercial CMOS process followed by single step of post anisotropic silicon etching of TMAH mixture without any additional protection of aluminum pads. The physical structure and fabrication process of microemitter is optimized to ensure high apparent temperature, fast response and high temperature survivability of emitter element along with low-cost, high-yield of manufacturing
International Symposium on Optoelectronic Technology and Application 2014: Infrared Technology and Applications, 2014
Optimization of indium bump preparation in infrared focal plane array (IRFPA) fabrication is pres... more Optimization of indium bump preparation in infrared focal plane array (IRFPA) fabrication is presented. Reasons of bringing defective pixels during conventional lift-off and cleanout process in fabrication of indium bump are discussed. IRFPAs are characterized by IRFPA test-bench. Results show that defective pixels of InSb IRFPA are owing to indium bumps connecting through indium residue on the surface of wafer. The characteristic and configuration of defective pixels of InSb IRFPA are given and analyzed. A method of reducing defective pixels through optimizing liftoff and cleanout process in InSb IRFPA is proposed. Results prove that this method is effective.
The semiconductor photonics and optoelectronics which have a great significance in the developmen... more The semiconductor photonics and optoelectronics which have a great significance in the development of advanced high technology of information systems will be discussed in this paper. The emphasis will be put on the recent research carried out in our laboratory in enhanced luminescence from low dimensional materials such as SiGe/Si and Er-doped Si-rich SiO2/Si and Er-doped Si x N y
Comparative electroluminescence (EL) and photoluminescence (PL) measurements were performed on Si... more Comparative electroluminescence (EL) and photoluminescence (PL) measurements were performed on Si/Si0.6Ge0.4 self-assembly quantum dots (QDs) structures. The samples were grown pseudomorphically by molecular beam epitaxy, and PIN diodes for electroluminescence were fabricated. Assisted TEM pictures shows the SiGe self-assembly QDs are plate-like. And it showed that the diameters of QDs are in range from 40 nm to 140 nm with the most in 120 nm. Both EL and PL has a wide luminescence peak due to wide distribution of QDs dimensions. At low temperature (T equals 14 K), EL peak has a red shift compared to the corresponding PL peak. Its full-width at half- maximum (FWHM) is about 97 meV, a little smaller than that of corresponding PL peak. The reasons of position and FWHM changes of EL peak from QDs have been discussed.
Athermal silica-based interferometer-type planar light-wave circuits were realized by a newly dev... more Athermal silica-based interferometer-type planar light-wave circuits were realized by a newly developed multicore fabrication method. In this method, inductively coupled plasma-enhanced chemical-vapor deposition and polishing technologies are adopted on a silica substrate with a trench-type waveguide pattern prepared by reactive ion etching. Two kinds of deposited core material, 10GeO 2 90SiO 2 (mol. %) and 8GeO 2 5B 2 O 3 87SiO 2 (mol. %), which show wavelength temperature dependence of 9.7 and 8.1 pm͞ ± C, respectively, were used to prepare the waveguide sections in a device. By adjustment of the lengths of waveguide sections with these two different core materials, athermal characteristics of less than 0.5 pm͞ ± C were achieved for Mach-Zehnder interferometer filter devices at the 1.55-mm wavelength range while the temperature varied from 220 to 80 ± C. The new method is also applicable for the preparation of many other kinds of functional devices.
Herein, we report a type II InAs/GaSb superlattice structure (SLS) grown on GaSb (100) substrates... more Herein, we report a type II InAs/GaSb superlattice structure (SLS) grown on GaSb (100) substrates by molecular beam epitaxy (MBE) and its electrical characterization for mid-wavelength infrared detection. A GaSb buffer layer was grown under optimized SLS growth conditions, which can decrease the occurrence of defects for similar pyramidal structures. The complications associated with these conditions include oxide desorption of the substrate, growth temperature of the SLS, the V/III ratio during superlattice growth and the shutter sequence. High-resolution X-ray diffraction (HRXRD) shows the sixth satellite peak, and the period of the SLS was 52.9 Å. The atomic force microscopy (AFM) images indicated that the roughness was less than 2.8 nm. High-resolution transmission electron microscopy (HRTEM) images indicated that the SLS contains few structural defects related to interface dislocations or strain relaxation during the growth of the superlattice layer. The photoresponse spectra indicated that the cutoff wavelength was 4.8 µm at 300 K. The SLS photodiode surface was passivated by a zinc sulfide (ZnS) coating after anodic sulfide.
... Ge atoms in the strained SiGe layer acting as momentum scattering centers can strengthen the ... more ... Ge atoms in the strained SiGe layer acting as momentum scattering centers can strengthen the overlap of electron and hole wave functions and greatly increase the NP (no-phonon) assisted optical transition probability [2]. The NP transition of quantum well (QW) structure has ...
Thermal stress accumulated in InSb infrared focal plane arrays (IRFPAs) during liquid nitrogen sh... more Thermal stress accumulated in InSb infrared focal plane arrays (IRFPAs) during liquid nitrogen shock tests usually gives rise to brittle fracture of InSb chips, local delamination between InSb chips and underfill. Upon the specific structure of the InSb IRFPAs installed in the Dewar, we propose the end surface circular ring fixed mode should be adopted to describe its boundary conditions instead of the well-accepted bottom surface center point fixed mode. From the created structure modeling of the InSb IRFPAs adopting the fixing modes mentioned above, we extract the thermal stresses and plot them together for easy comparison. We find that the end surface circular ring fixed mode is superior to the wellaccepted bottom surface center point fixed mode in aspects of the considerable reduction of the thermal stress in the InSb chips, the moderate decrease of both the shear stress and the peeling off stress between the InSb chips and the underfill. All these findings suggest that the thermal stress of the InSb IRFPAs assembled in the Dewar is overestimated by the well-accepted bottom surface center point fixed mode and can be greatly decreased by adjusting its fixing mode.
Three-dimensional equivalent modeling of InSb IRFPAs is created in this paper. Z-components of st... more Three-dimensional equivalent modeling of InSb IRFPAs is created in this paper. Z-components of strain are employed to display deformation distribution characteristics. Design rule of indium bump is proposed, that is, the diameter of indium bump is not larger than 0.4 times element pitch. Design rule of indium bump is verified by series IRFPAs with different formats.
AOPC 2015: Optical Design and Manufacturing Technologies, 2015
One of the major challenges of InAs/GaSb superlattice devices arises owing to the large number of... more One of the major challenges of InAs/GaSb superlattice devices arises owing to the large number of surface states generated during fabrication processes. Surface passivation and subsequent capping of the surfaces are essential for any practical applicability of this material system. In this paper, we passivated InAs/GaSb superlattice infrared detectors proposed anodic fluoride passivation method. Short and mid wavelength InAs/GaSb superlattice infrared materials were grown by Molecular Beam Epitaxy (MBE) on GaSb (100) substrates. A GaSb buffer layer was grown for optimized superlattice growth condition, which can decrease the occurrence of defects with similar pyramidal structure. The result of auger electron spectroscopy (AES) surface scans after anodic fluoride passivation confirms that anodic fluoride passivation treatment did affect. The leakage current as a function of bias voltage (I-V) for InAs/GaSb superlattice infrared detectors has been examined at 77K. Compared with the unpassivated approach, this passivation methods decrease the dark current by approximately five orders of magnitude.
2012 12th International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD), 2012
The quantum efficiency (QE) for mid-wavelength InSb infrared focal plane arrays has been numerica... more The quantum efficiency (QE) for mid-wavelength InSb infrared focal plane arrays has been numerically studied. Effects of the absorption length and thickness of p-region on device QE have been investigated. Our work shows that the optimum thickness of p-region is largely dependent on the absorption characteristics of the InSb.
Abstract Photodiodes of InSb were fabricated on an epitaxial layer grown using molecular beam epi... more Abstract Photodiodes of InSb were fabricated on an epitaxial layer grown using molecular beam epitaxy (MBE). Thermal cleaning of the InSb (0 0 1) substrate surface, 2° towards the (1 1 1) B plane, was performed to remove the oxide. Photodiode properties of МВЕ-formed epitaxial InSb were demonstrated. Zero-bias resistance area product ( R 0 A ) measurements were taken at 80 K under room temperature background for a pixel size of 100 μm × 100 μm. Values were as high as 4.36 × 10 4 Ω/cm 2 , and the average value of R 0 A was 1.66 × 10 4 Ω/cm 2 . The peak response was 2.44 (A/W). The epitaxial InSb photodiodes were fabricated using the same process as bulk crystal InSb diodes with the exception of the junction formation method. These values are comparable to the properties of bulk crystal InSb photodiodes.
An infrared (IR) dual band multi-element detector with the abilities of dual band IR countercount... more An infrared (IR) dual band multi-element detector with the abilities of dual band IR countercountermeasure (IRCCM) and spatial filtering is presented for effective target detection in a complex tactical environment. The detection elements of the detector are specially arranged like a conventional reticle pattern. With special design, the ratio of radiation intensity from two IR bands can be calculated to distinguish the target from the IR target-flare mixed signal and the two detection bands use a common aperture in the seeker. Without a reticle in the optical system of the IR seeker, the dual band detector can still perform spatial filtering to eliminate background noise effectively. The design details of the detector are presented. The performance of the detector's dual band IRCCM and spatial filtering are analyzed. Simulation results are presented verifying validity of the presented method.
The quantum efficiency for mid-wavelength InSb infrared focal plane arrays has been numerically s... more The quantum efficiency for mid-wavelength InSb infrared focal plane arrays has been numerically studied by two dimensional simulators. Effects of thickness of p-type layer on the quantum efficiency under front-side illumination have been obtained. The calculated results can be used to extract the optimal thickness of the p-type layer for different absorption and diffusion lengths. It is indicated that the optimal thickness of the p-type layer strongly depends on the absorption coefficient and the minority carrier lifetimes. The empirical formulas are also obtained to describe the correlation between the optimal thickness of the p-type layer, and the absorption and diffusion lengths.
Indium bumps are generally accepted to possess functions of electrical connection, mechanical sup... more Indium bumps are generally accepted to possess functions of electrical connection, mechanical support and heat transfer in flip-chip devices. After comparing the distribution of stress components along different paths in InSb infrared focal plane arrays (IRFPAs), we ascertain that local enhancement effects of the stress components are remarkable in regions where the indium bumps are. More specifically, the local enhanced tensile stress in InSb chip connected with the indium bumps can lead to the local fracture of the InSb chip, and the locally enhanced shear and peeling stresses may give rise to the local interfacial delamination between the InSb chip and the indium bumps. These inferences are confirmed by the observed local failure characteristics, such as the distribution of the local delamination, the distribution of the crack widths, and the distribution of the cracks. In addition, the simulated Z-component strain distribution in InSb IRFPAs is also consistent with the backside surface profile of the InAs/GaSb IRFPAs fabricated in America with the identical structure, that is, the InSb chip glued with the indium bumps is concave downward, and the InSb chip glued with the underfill is convex upward. Judging from all these confirmed simulation results, we are confident that the indium bumps play a pivotal role in inducing the local failure of InSb IRFPAs. So the role of the indium bumps in causing the local failure of InSb IRFPAs needs to be supplemented and emphasized to comprehensively evaluate the structural reliability of InSb IRFPAs.
Thermal annealing effect on electrical properties of the Pt/Al0.45Ga0.55N Schottky contacts is in... more Thermal annealing effect on electrical properties of the Pt/Al0.45Ga0.55N Schottky contacts is investigated. The ideality factor, barrier height, and series resistance are obtained from the forward I-V characteristics of the Pt/Al0.45Ga0.55N Schottky contacts. For the Schottky contacts without annealing, the ideality factor decreases from 1.77 to 1.50, and series resistance decreases from 213 Ω to 126 Ω, and the barrier height increases from 1.00 to 1.18 eV with increasing temperature. For the Schottky contacts annealed in nitrogen ambient at 450°C for 1 min, the ideality factor decreases from 2.18 to 1.58, and series resistance decreases from 363 Ω to 207 Ω, and the barrier height increases from 0.77 to 1.04 eV with increasing temperature in a temperature range of 198-298 K. The ideality factor and series resistance of the Schottky contacts with annealing are higher than those without annealing, while the barrier height is lower than that without annealing at various temperatures. Variation of the ideality factor with temperature is good agreement with TFE theory. TFE theory analysis shows that the characteristic energy of 36.0 meV for the Schottky contacts with annealing is greater than 19.3 meV for that without annealing, which should be attributed to much more N vacancy produced at the interface between Pt and Al0.45Ga0.55N as a donor impurity due to annealing.
A novel chip pattern with extinction function in Lead salt detectors is specified. Lead Sulfide (... more A novel chip pattern with extinction function in Lead salt detectors is specified. Lead Sulfide (PbS) polycrystalline film is prepared by Chemical Bath Deposition (CMD) on a transparent substrate, then a special figure and structure is saved by lithography techonology on the substrate. As a quaternion detector chip that made by PbS thin film for example in this paper, whose performance including signal, noise, weak-peaks and the uniformity of the chip are too poor to meet the detecting system at the initial stage of research, and the qualified ratio of chips is only 3% .This paper explains the reason why the performance and qualified ratio of chips were so poor, focuses on a novel chip pattern with extinction which avoided the disadvantages of traditional one. the novel chip pattern has been applied in detectors. The novel chip pattern is prepared with PbS thin film which both “extinction slice” and detector chip are based on a same substrate , which not only had absorbed the jumbled light , improved the uniformity and other performance of photosensitive elements, but also had left out the assembly diffculty and precision demand when a extinction slice assembly in the restricted space of inswept detector chip, omitted the production process of extinction slice and shorten the assembly process of the detectors, and the qualified ratio of chips had been improved from 3% to 98%.
International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Infrared Imaging and Applications, 2009
Au-Al 0.30 Ga 0.70 N Lateral Schottky photodiode was fabricated by an electrical breakdown of a s... more Au-Al 0.30 Ga 0.70 N Lateral Schottky photodiode was fabricated by an electrical breakdown of a single Schottky barrier of metal-semiconductor-metal Au-Al 0.30 Ga 0.70 N film rocking curves are about 523.7 arcsec for the (00.2) plane reflection and about 989.5 arcsec for the ...
This paper gives the example of making infrared wire grid polarizer used in 8 to approximately 14... more This paper gives the example of making infrared wire grid polarizer used in 8 to approximately 14 micrometers wave range by ion beam milling. We have measured and calculated the transmissibility and polarizability of the polarizer. The results have been analyzed and compared with those derived from the theory. it is illustrated that we can get uniform and better quality polarizer by using this method.
2006 8th International Conference on Solid-State and Integrated Circuit Technology Proceedings, 2006
An improved thermally isolated bulk-silicon-micromachined microemitter that can be applied for dy... more An improved thermally isolated bulk-silicon-micromachined microemitter that can be applied for dynamic infrared scene projectors has been fabricated using commercial CMOS process followed by single step of post anisotropic silicon etching of TMAH mixture without any additional protection of aluminum pads. The physical structure and fabrication process of microemitter is optimized to ensure high apparent temperature, fast response and high temperature survivability of emitter element along with low-cost, high-yield of manufacturing
International Symposium on Optoelectronic Technology and Application 2014: Infrared Technology and Applications, 2014
Optimization of indium bump preparation in infrared focal plane array (IRFPA) fabrication is pres... more Optimization of indium bump preparation in infrared focal plane array (IRFPA) fabrication is presented. Reasons of bringing defective pixels during conventional lift-off and cleanout process in fabrication of indium bump are discussed. IRFPAs are characterized by IRFPA test-bench. Results show that defective pixels of InSb IRFPA are owing to indium bumps connecting through indium residue on the surface of wafer. The characteristic and configuration of defective pixels of InSb IRFPA are given and analyzed. A method of reducing defective pixels through optimizing liftoff and cleanout process in InSb IRFPA is proposed. Results prove that this method is effective.
The semiconductor photonics and optoelectronics which have a great significance in the developmen... more The semiconductor photonics and optoelectronics which have a great significance in the development of advanced high technology of information systems will be discussed in this paper. The emphasis will be put on the recent research carried out in our laboratory in enhanced luminescence from low dimensional materials such as SiGe/Si and Er-doped Si-rich SiO2/Si and Er-doped Si x N y
Comparative electroluminescence (EL) and photoluminescence (PL) measurements were performed on Si... more Comparative electroluminescence (EL) and photoluminescence (PL) measurements were performed on Si/Si0.6Ge0.4 self-assembly quantum dots (QDs) structures. The samples were grown pseudomorphically by molecular beam epitaxy, and PIN diodes for electroluminescence were fabricated. Assisted TEM pictures shows the SiGe self-assembly QDs are plate-like. And it showed that the diameters of QDs are in range from 40 nm to 140 nm with the most in 120 nm. Both EL and PL has a wide luminescence peak due to wide distribution of QDs dimensions. At low temperature (T equals 14 K), EL peak has a red shift compared to the corresponding PL peak. Its full-width at half- maximum (FWHM) is about 97 meV, a little smaller than that of corresponding PL peak. The reasons of position and FWHM changes of EL peak from QDs have been discussed.
Athermal silica-based interferometer-type planar light-wave circuits were realized by a newly dev... more Athermal silica-based interferometer-type planar light-wave circuits were realized by a newly developed multicore fabrication method. In this method, inductively coupled plasma-enhanced chemical-vapor deposition and polishing technologies are adopted on a silica substrate with a trench-type waveguide pattern prepared by reactive ion etching. Two kinds of deposited core material, 10GeO 2 90SiO 2 (mol. %) and 8GeO 2 5B 2 O 3 87SiO 2 (mol. %), which show wavelength temperature dependence of 9.7 and 8.1 pm͞ ± C, respectively, were used to prepare the waveguide sections in a device. By adjustment of the lengths of waveguide sections with these two different core materials, athermal characteristics of less than 0.5 pm͞ ± C were achieved for Mach-Zehnder interferometer filter devices at the 1.55-mm wavelength range while the temperature varied from 220 to 80 ± C. The new method is also applicable for the preparation of many other kinds of functional devices.
Herein, we report a type II InAs/GaSb superlattice structure (SLS) grown on GaSb (100) substrates... more Herein, we report a type II InAs/GaSb superlattice structure (SLS) grown on GaSb (100) substrates by molecular beam epitaxy (MBE) and its electrical characterization for mid-wavelength infrared detection. A GaSb buffer layer was grown under optimized SLS growth conditions, which can decrease the occurrence of defects for similar pyramidal structures. The complications associated with these conditions include oxide desorption of the substrate, growth temperature of the SLS, the V/III ratio during superlattice growth and the shutter sequence. High-resolution X-ray diffraction (HRXRD) shows the sixth satellite peak, and the period of the SLS was 52.9 Å. The atomic force microscopy (AFM) images indicated that the roughness was less than 2.8 nm. High-resolution transmission electron microscopy (HRTEM) images indicated that the SLS contains few structural defects related to interface dislocations or strain relaxation during the growth of the superlattice layer. The photoresponse spectra indicated that the cutoff wavelength was 4.8 µm at 300 K. The SLS photodiode surface was passivated by a zinc sulfide (ZnS) coating after anodic sulfide.
... Ge atoms in the strained SiGe layer acting as momentum scattering centers can strengthen the ... more ... Ge atoms in the strained SiGe layer acting as momentum scattering centers can strengthen the overlap of electron and hole wave functions and greatly increase the NP (no-phonon) assisted optical transition probability [2]. The NP transition of quantum well (QW) structure has ...
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Papers by Junjie Si