Microscopic and Elemental Mapping of InSbBi Substrate of Bulk Crystal Grown by VDS (original) (raw)
Related papers
2013
Vertical Directional Solidification (VDS) Technique was used for the bulk growths of InSb1-xBix semiconductor without seed for x = 0.04 and x = 0.06. The source materials were filled with argon in the quartz ampoules at the pressure 200 torr. The ampoules were synthesized for 48 hr at temperature 850 o C. Temperature gradient at the solid- liquid interface was of the order of 20 o C/cm. The ampoules were rotated at the speed of 12 rpm during the synthesis as well as the growth. The grown ingots were annealed at 250 o C for 48 hr. These two growths were carried out at the growth rate of 5mm/hr. In both the cases the composition of the source materials (Indium, antimony and Bismuth) in the grown crystals was estimated by EDAX analysis. An equal amount of InSbBi from each of the two ingots was filled in the new ampoule with argon pressure 200 torr and the growth was carried out at the growth rate of 3 mm/hr and rotation speed 12 rpm. The grown ingot was n-type semiconductor with mobili...
The VDS technique was used for the crystal growth of InSb1-xBix. The source materials were filled with argon in a quartz ampoule of cone angle <200 at one end at pressure 200 torr. The ampoules were synthesized for 40-50 hrs at 850oC temperature. Five growths of InSb1-xBix bulk semiconductor crystal were carried out at the growth rate varying from 2 to 6 mm/hr and various values of x. Temperature gradient at the solid liquid interface was in the range of 18 oC/cm to 20 oC/cm. The grown ingots were sliced to 450 – 600 mm thickness along the axis and perpendicular to the axis. One growth resulted in p-type semiconductor while the other four resulted in n-type semiconductor. The growth rate of 2 mm/hr show good quality single crystal with maximum mobility up to 44500 cm2/V s at room temperature (300oC), while the higher growth rate produce poor crystal quality (polycrystalline) material. The result of second growth (x=0.05) shows that the material is semiconductor having resistivity...
Fabrication and characterization of n -InSb thin film of different thicknesses
2013
The n-type indium antimonide thin films of the thickness 300-1200 nm were fabricated by electron beam evaporation technique on ultrasonically cleaned glass substrates at room temperature using optimized starting material. The X-ray diffraction patterns reveal that films are polycrystalline with zincblende structure. The dependence of structural, electrical and optical properties on film thickness was studied and optimized the film thickness. The Scanning Electron Microscope (SEM) micrographs show that the films are smooth and compact with larger grains. The electrical resistivity decreases (0.66-0.13)10 ohm.cm with increase of film thickness. These fabricated thin films show semiconducting behaviour because its conductivity increases with increase of temperature. The Hall effect measurement indicates that the films are of n-type having carrier concentration (0.45-0.17)10 cm and mobility (2.11-30.42)10 cm/V.s. The direct band gap has been calculated by Fourier Transform Infrared (FTI...
Bulk growth of InSb crystals for infrared device applications
Journal of Crystal Growth, 1999
High-quality indium antimonide crystals, suitable for infrared device applications, were grown by vertical Bridgman technique. An indigenous Bridgman setup with some modifications was employed for this purpose. A series of experiments were carried out with different ampoule lowering rate, axial temperature gradient and ampoule cone angle in order to optimise the growth conditions. The grown crystals were subjected to XRD and EDX analyses to assess chemical homogeneity. Chemical etching revealed no observable variation in defect-density distribution. Electrical properties were also studied along the length of the crystal. IR transmittance studies, carried out on a sample 1.5 cm in diameter and 300 m in thickness, revealed the high-percentage transmittance and sharp cutoff at shorter wavelength end which are the essential conditions for an infrared filter.
Indian Journal of Engineering and Materials Sciences, 2006
Thin films of InSb nanocrystals have been deposited onto KCl substrate using a thermal evaporation technique under high vacuum conditions (∼10-6 torr). An intriguing microstructure consisted of moiré fringes with variable spacings and a corresponding variety of electron diffraction patterns in reciprocal space are reported at the deposition temperature of 373 K. The nanograins of InSb with preferred orientation and faceted morphology are delineated. A possible mechanism has been postulated to explain the evolution of such microstructures. It has been noticed that there is a peculiarity in the resistivity characteristics and infrared transmittance measurements obtained on these films. A set of electron micrographs, diffraction patterns and properties have been evaluated and discussed to understand the role of nanocrystals constituting the thin film, and certain types of defects introduced in the microstructure while deposition, on these properties.
Rietveld x-ray powder analysis of Inbi crystalline structure at low temperatures
Journal of Alloys and Compounds, 1993
The dependence of the InBi crystalline structure on temperature (between 300 and 15 K) has been refined by the Rietveld method from X-ray powder diffraction data. The ranges of the lattice parameters (a and c) and the free parameter of the Bi atom (z) in the above temperature range are 5.0101 -4.9589(3) A, 4.7824(3)-4.8396(3) /~ and 0.3993(7)-0.3918 respectively.
Journal of Semiconductors, 2011
The crystal structure of InSb [111] A/B surfaces shows that this structure is polarized. This means that the surfaces of InSb [111] A and InSb [1 1 1] B contain two different crystallized directions and they have different physical and chemical properties. Experiments were carried out on the InSb [111] A/B surfaces, showing that tartaric acid etchant could create a very smooth surface on the InSb [1 1 1] B without any traces of oxides and etch pit but simultaneously create etch pit on InSb [111] A surfaces. After lapping and polishing, some particles remained on the InSb [ B surface, they could not be removed easily by standard cleaning process and if these particles remain on the surface of the substrate, the growth layer was not uniform and some island-like regions were observed. The purpose of this work is to remove these particles on the InSb [1 1 1] B surface. Some morphology images of both surfaces, InSb [111] A/B, will be presented.
Wet Etching Characterization of InSb for Thermal Imaging Applications
Japanese Journal of Applied Physics, 2006
A citric acid/hydrogen peroxide-based chemical system has been reported for the first time to meet the requirements of continuously scaling down the pixel area for InSb high-density infrared camera applications. This chemical system with a reaction-rate-limited mechanism was concluded to have superior etching performance compared with the nitric acid-based solution. It is established that this etching mechanism has better control over device structure uniformity due to its linear proportionality to etching time and its nondependence on agitation and exposed etched area. Two different chemical systems have been studied to form the high-density mesa structures in this study. The wet etching characteristics corresponding to these chemical solutions were measured and analyzed. From atomic force microscopy (AFM), the results clearly indicate that the surface-reaction-rate-limited dominant-control mechanism for InSb mesa etching in citric acid/hydrogen peroxide produces a fairly smooth morphology near junction edges and well-controlled sidewall profiles. Good step coverage for dielectric deposition as shown by field-emission scanning electron microscopy and a highly uniformly distributed dark current of InSb pn junction arrays at 77 K have proven the feasibility of the citric acid/hydrogen peroxide wet etching process to bring superior etching performance compared with the nitric acid-based solution.
Characterization of secondary phases formed during MOVPE growth of InSbBi mixed crystals
Journal of Crystal Growth, 2000
Secondary phases, formed during the growth of InSbBi, a III}V compound with potential for infrared applications in the 8}12 m range, are reported. Layers were prepared by atmospheric pressure metal-organic vapour-phase epitaxy at 4553C in a horizontal quartz reactor. The source materials used were trimethylindium (TMIn), trimethylantimony (TMSb), and trimethylbismuth (TMBi). Scanning electron microscopy and X-ray di!raction spectra showed the formation of extra phases on the surfaces of the layers. The compositions of these condensed phases were in#uenced by the V/III ratio at the growth interface. Bi precipitates were observed by cross-sectional transmission electron microscopy for layers grown on InSb substrates. Attempts to grow InSbBi on GaAs substrates produced InAsSb layers. The As composition showed a dependence on the availability of Bi, increasing from 7.5 to 26 mol% InAs when increasing the Bi/V ratio from 0.04 to 2%. The incorporation of As has been related to the formation of Bi}Ga inclusions at the GaAs interface.
Improvement the InAs, InSb, GaAs and GaSb surface state by nanoscale wet etching
Applied Nanoscience, 2021
Various experimental approaches of the wet nanoscale treatment have been proposed to account for features of the InAs, InSb and GaAs, GaSb semiconductor dissolution process in the (NH4)2Cr2O7–HBr–EG etching solution. Etching kinetics data showed that a crystal dissolution has diffusion-determined nature. The lowering of the solvent concentration from 80 to 0 vol.% in the solution was accompanied by a significant increase in the semiconductor etching speed. Depending on the solution composition, we have studied two types of crystal surface morphology, polished and passivated by the film, which was formed after chemical-dynamic (CDP) and/or chemical-mechanic polishing (CMP) in the solution, saturated by solvent and by oxidant, accordingly. It was found that in the polished etchants both CDP and CMP procedures lead to the formation of the mirror-like and super-smooth surface with nanoscale roughness less than 1 nm. The obtained results of surface state indicate that the (NH4)2Cr2O7–HBr...