Junjie Si - Academia.edu (original) (raw)

Papers by Junjie Si

Optical and Quantum Electronics, 2019

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.

SPIE Proceedings, 2012

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.

SPIE Proceedings, 2015

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 ...

SPIE Proceedings, 1996

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.

Czechoslovak Journal of Physics, 1999

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.

Optics Letters, 2003

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.

Infrared Physics & Technology, 2014

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.

Solid State Communications, 1999

... 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 ...