摘要:

The series of workshops on the Physics and Chemistry of Mercury Cadmium Telluride (MCT) and related compounds has been in existence for about ten years now. It is worthwhile to take a look at its origins; the progress in these past ten years and some projections for the next ten years as we prepare to enter teh 21st century.

ISSN:0094-243X    

DOI:10.1063/1.41086

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The key diffusion quantities for component diffusion in mercury cadmium telluride are reviewed: interdiffusion; intrinsic diffusion; and tracer self‐diffusion. The interrelation between these qiantities is described as well as their relation to practical diffusion problems. A review of the experimental information for these diffusion quantities is presented in the framework of diffusion theory and diffusion mechanisms. In particular, the interrelation between the fundamental diffusion quantities is used to assign diffusion values. The interpretation of marker motion and Kirkendall effect experiments is presented in the context of theory and experimental diffusion information in this system.

ISSN:0094-243X    

DOI:10.1063/1.41087

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Hg1−xCdxTe layers grown by organometallic vapor phase epitaxy areptype with carrier concentrations around 4×1016/cm3due to group II vacancies. Following a Hg saturated anneal at 220 °C for 25 h, these layers becomentype with carrier concentrations around 5×1014/cm3. However, the presence of a 0.5–0.8 &mgr;m thick CdTe cap inhibits the annealing of the underlying Hg1−xCdxTe layer, since it acts as a barrier for Hg diffusion. By opening windows in this cap, the underlying Hg1−xCdxTe layer can be annealed and converted tontype in a selective manner.P–Njunction photodiodes were fabricated using this planar technique. Some of these diodes employed the CdTe cap itself as the surface passivant; in others, the CdTe cap was stripped and anodic sulfide was used as the junction passivant. In both the cases, diodes hasR0Avalues comparable to the best values reported in literature.N‐channel enhancement mode metal‐insulator semiconductor field effect transistors were also fabricated using anodic sulfide as the surface passivant. Here, then‐type source and drain regions were formed by selectively annealing the as grownp‐type Hg1−xCdxTe layer.

ISSN:0094-243X    

DOI:10.1063/1.41098

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

HgCdTe was grown by the metalorganic chemical vapor deposition alloy process on (111)B CdTe/GaAs and (111)B CdTe substrates at 300 °C using diisopropyltelluride, dimethlycadmium, and elemental mercury. Excellent surface morphology and compositional uniformity were obtained at this temperature. Hall effect measurements indicate thatn‐type (111) HgCdTe with carrier concentration below 1015cm−3and good mobilities at 77 K can be obtained on GaAs substrates.

ISSN:0094-243X    

DOI:10.1063/1.41088

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We have measured the growth rate dependence of CdTe and HgTe layers in the growth surface direction. The growth mechanism of HgTe and CdTe were concluded to be heterogeneous, surface kinetic limited. The morphology of CdTe and mercury cadmium telluride interdiffusion multilayer process layers is found to be strongly effected by the large anisotropy of the CdTe growth rate. The best morphologies were found to be on surfaces having directions of maximum CdTe growth rates, with respect to surfaces of other crystallographic directions. A model for hillocks formation is given, based on the CdTe growth rate anisotropy. The different nature of twins stacking faults in (111)A and (111)B layers is explained by the different morphologies of these layers.

ISSN:0094-243X    

DOI:10.1063/1.41089

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We report on the growth and characterization of mercury cadmium telluride (MCT) heterostructures grown by isothermal vapor phase epitaxy (ISOVPE) and vapor phase epitaxy (VPE). This report consists of the use of both ISOVPE and VPE methods for growing wider band gap MCT on narrow band gap MCT, the compositional and structural characterization of as‐grown layers, and the use of two zone Hg ampoules for carrier concentration control. The crystal perfection of some heterostructures is as good as that of the ISOVPE‐grown layers. The carrier concentrations and mobilities of the ISOVPE‐grown layers are substantially improved by a two zone Hg annealing technique.

ISSN:0094-243X    

DOI:10.1063/1.41090

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Post growth thermal annealing has been used to reduce the threading dislocation density of Hg1−xCdxTe (0.20≤x≤0.28) epilayers grown on (211)B GaAs substrates by molecular beam epitaxy. Etch pit density studies indicate an order of magnitude reduction on the surface threading dislocations after annealing at 490 °C for 30 min. The dislocation density at the HgCdTe surface on this highly mismatched system is only a factor of 2–6 times higher than the best values (1×105cm−2) we have obtained using CdZnTe bulk lattice‐matched substrates. The reduction of dislocations may be due to enhanced dislocation movement and their annihilation and coalescence at Hg vacancies point defect pinning centers introduced during the annealing process.

ISSN:0094-243X    

DOI:10.1063/1.41091

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We have grown CdTe directly on 2‐ and 5‐in. diam Si(100) by molecular‐beam epitaxy and characterized the layers byin situreflection high‐energy electron diffraction, double crystal x‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and low‐temperature photoluminescence. The films are up to 10‐&mgr;m thick and mirror‐like over their entire surface. Even on 5‐in. diam wafers, the structural and thickness uniformity is excellent. Two domains, oriented 90° apart, are observed in the CdTe films on oriented Si(100) substrates, whereas single‐domain films are grown on Si(100) titled 6° or 8° toward [011]. The layers on misoriented substrates have better morphology than those on oriented Si(100), and the substrate tilt also eliminates twinning in the CdTe layers. First attempts to grow HgCdTe on Si(100 with a CdTe buffer layer have produced up to 10‐&mgr;m thick layers with cutoff wavelengths between 5 and 10‐&mgr;m and with an average full width at half‐maximum of the double‐crystal x‐ray diffraction peaks of 200 arc s.

ISSN:0094-243X    

DOI:10.1063/1.41092

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Detailed characterization of chemical beam epitaxially (CBE) grown CdTe and Hg1−xCdxTe layers are reported. These characterizations include photoluminescence, infrared transmission, energy dispersive x‐ray analysis, and variable temperature (10–300 K) Hall effect and resistivity measurements. The results indicate that high quality HgCdTe layers can be grown by CBE.

ISSN:0094-243X    

DOI:10.1063/1.41072

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Consistently low dislocation density midwavelength infrared (x=0.31) liquid phase epitaxy HgCdTe epitaxial layers with excellent morphology were grown on 2 in. sapphire substrates (PACE‐1) usiing a new low‐temperature (420 °C)Te melt process. Surface etch pit densities (EPDs) between 5×105and 9×105cm−2were revealed using a previously reported chemical etch (J. S. Chen, US Patent No. 4897152) on a 20‐layer sample set. Cross‐sectional EPD profiles reveal a more rapid decrease of defects from the CdTe buffer layer interface as compared to conventionally grown (500 °C) material. X‐ray rocking curve widths from 43 to 66 arcsec were routinely observed. 77 K electron mobilities as high as 51 000 cm2/V‐s were measured. Secondary‐ion mass spectrometry profiles show a minimum of impurity gettering at the HgCdTe/CdTe buffer layer interface.

ISSN:0094-243X    

DOI:10.1063/1.41073

出版商:AIP    

年代:1991

数据来源: AIP