摘要:

Heavily dopedn‐type InP and InGaAs epitaxial layers have been grown by metalorganic chemical vapor deposition at atmospheric pressure using tetraethyltin (TESn) as a dopant source. Sn‐doped InP and InGaAs layers have been grown with doping concentrations as high asn300K∼3.3×1019cm−3andn300 K∼6.1×1019cm−3, respectively. Hall measurements ofNd‐Naat 300 and 77 K indicate that the Sn is uncompensated up to these concentrations. Analysis of the Sn concentration in InP:Sn and InGaAs:Sn layers using secondary ion mass spectrometry, shows that all of the Sn is ionized in InP and InGaAs until a limit is reached that corresponds to the electrical limits. SIMS profiles also show that the use of TESn for the growthn+InP and InGaAs layers results in no severe memory effects and that abrupt Sn doping profiles can be achieved.

ISSN:0021-8979    

DOI:10.1063/1.345072

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The electrical, physical, and chemical characteristics of plasma‐assisted chemical‐vapor deposited semi‐insulatinga‐SiN:H for use as a resistive field shield to passivate high voltage integrated circuits are summarized. The films were deposited onto the devices in a hot wall horizontal tube plasma reactor using NH3and SiH4. The stoichiometry, refractive index, stress, structure, deposition rate, thermal stability, electrical properties, and sodium penetration resistance were determined. The chemical, physical, and mechanical properties of the film are controlled by the NH3/SiH4flow ratio. The N/Si ratio decreased linearly from 1/2 at a 5/1 NH3/SiH4flow ratio to 0.15/1 at a 1/2 NH3/SiH4flow ratio. This decrease in nitrogen content manifests itself as an increase in the refractive index from 2.1 to 3.1. Using the random bonding model, we show that the bond strength decreases and effective bond length increases with decreasing N/Si ratio. The decrease in bond strength causes a decrease in the thermal stability of the film because hydrogen evolution is more easily achieved. The increase in bond length increases the magnitude of the compressive film stress. The electrical properties of the films are also controlled by the N/Si ratio. For example, the conductivity at 25 °C and 1 MV/cm increases from approximately 1×10−18(&OHgr; cm)−1to approximately 2×10−7(&OHgr; cm)−1when the N/Si ratio decreases from 1.1/1 to 0.15/1. The conductivity data are consistent with a Frenkel–Poole mechanism. SinSiN films with conductivities between 10−11and 10−14(&OHgr; cm)−1measured at 2.4×105V/cm and 25 °C were successfully applied to high voltage ICs. These films did not affect the device yield, but did yield devices which were immune to surface ions. The average breakdown voltage of the high voltage devices passivated with semi‐insulatinga‐SiN:H was increased by 20–40 V over those passivated with insulatinga‐SiN:H.

ISSN:0021-8979    

DOI:10.1063/1.345073

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Nucleation of dislocations within a strained multilayer and at a singular or vicinal multilayer surface is considered for typical compound semiconductor and metal cases. The results indicate that strained multilayer structures are stable against dislocation injection, even when the layer thickness exceeds the thermodynamic critical thickness for misfit dislocation stability, in the absence of defects or large external stresses. An exact energy calculation for spreading of a threading dislocation in GaAs layer is also presented. The results show that in the absence of any jog formation, there is no barrier to spreading at or above the thermodynamic, Matthews–Blakeslee critical layer thickness. Moreover, reversible spreading to an equilibrium standoff distance occurs for thicknesses smaller than the critical thermodynamic value, an effect that can lead to dissipative reversed dislocation motion under alternating driving forces.

ISSN:0021-8979    

DOI:10.1063/1.345074

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The effect of deposition conditions on the structure and composition of plasma deposited silicon nitride films was studied using x‐ray photoelectron spectroscopy. Plasma deposited silicon nitride films were transferred directly from the deposition chamber into a surface analysis system, thereby permitting analysis of as‐deposited films without modification due to ion sputtering. Plasma deposited silicon nitride films with N:Si ratios from 1.8–0.3 were deposited using SiH4, NH3, N2, and H2as the source gases. The N:Si ratio in the films increased with increasing nitrogen concentration in the gas phase. Changes in the deposition power or the substrate temperature also influenced the N:Si ratio. Large differences in the film structure were observed for plasma deposited silicon nitride films formed with NH3compared to N2with respect to deposition temperature variations.

ISSN:0021-8979    

DOI:10.1063/1.345075

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The strain relaxation of CdTe(100) layers grown on GaAs(100) substrates by hot‐wall epitaxy was investigated by measurement of optical properties, x‐ray analysis, and transmission electron microscopy. It is considered from transmission electron microscopy observation that relaxation of most of the strain due to lattice mismatch occurred at the interface. However, a small amount of strain, of the order of 10−3, remained in layers thicker than 0.7 &mgr;m, and it was relaxed as the layer thickness increased. The residual strain of 4×10−4, which exists in layers thicker than 10 &mgr;m, was due to the difference between the thermal expansion coefficients of the layer and the substrate. Moreover, for layers thicker than 17 &mgr;m, split ground (n=1) and first excited (n=2) free‐exciton states due to internal strain have for the first time been observed by photoluminescence and reflectance spectroscopy. The results show that CdTe layers with excellent crystallinity and homogeneity in strain are obtained.

ISSN:0021-8979    

DOI:10.1063/1.346079

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

X‐ray photoelectron spectroscopy and Auger electron spectroscopy measurements were performed to investigate the initial growth mechanism and the selection of growth orientations of CdTe layers grown on (100) GaAs by metalorganic vapor phase epitaxy (MOVPE). The surface stoichiometry of the GaAs substrate was found to recover when annealed in a H2flow atmosphere (500 °C, 5 min), although the surface was initially in an As‐rich condition after chemical etching by H2SO4@B:H2O2@B:H2O=5@B:1@B:1. No oxide was observed at both the etched and H2annealed GaAs surfaces. Preferential adsorption of Te occurred on the GaAs surface when H2annealing was carried out in the growth reactor in the presence of residual CdTe deposits. One monolayer of Te with a thickness of about 1.8 A˚ was adsorbed on the GaAs surface when the H2annealed GaAs was exposed to diethyltelluride during the cooling period from the annealing temperature to the growth temperature (420 °C). On the other hand, minimal adsorption of Cd occurred when the H2annealed GaAs was exposed to dimethylcadmium during the above period. (100) CdTe growth was reproducibly achieved when the GaAs surface was completely covered by one monolayer of Te before growth, otherwise (111) growth occurred. Differences in the initial growth mechanism between MOVPE and molecular‐beam epitaxy are also discussed.

ISSN:0021-8979    

DOI:10.1063/1.345076

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Two types of epitaxial films of lutetium diphthalocyanine, LuPc2, have been obtained on KBr, LuPc2/KBr, and on the film of fluoro‐bridged aluminum phthalocyanine polymer, (AlPcF)n, on KBr, LuPc2/(AlPcF)n/KBr, by the molecular beam epitaxy technique. Their structures have been studied by transmission electron microscopy as well as scanning electron microscopy. The phase of LuPc2/KBr is bidirectionally oriented tetragonal, KBr(100)((10)1/2×(10)1/2)R±27°‐LuPc2. The phase of LuPc2/(AlPcF)n/KBr is predominantly unidirectionally oriented tetragonal, KBr(100)(3×3)R45°‐LuPc2/(AlPcF)n, but some bidirectional orthorhombic phase, KBr(100)C(6×3)R45°‐LuPc2/(AlPcF)n, is also present.

ISSN:0021-8979    

DOI:10.1063/1.345077

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Evaporated gold films and gold films etched by argon ion bombardment to the same thickness are known to exhibit different optical and electrical properties. Transmission electron microscope observations presented in this paper confirm that these differences are caused by different growth/etch film morphologies. The density of islands in a globular film remains nearly constant during etching, in contrast to a steady decrease during deposition. Similarly, the particle density in a nested island film initially remains constant during etching but then increases slightly as some of the islands break up. Films that are initially fully coalesced remain continuous during etching until, when they are very thin, an array of holes of irregular shape and increasing size appears and finally they break up into islands of irregular shape.

ISSN:0021-8979    

DOI:10.1063/1.345078

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Measurements of deep‐level properties of Mn in InP are reported. Hall effect and deep‐level transient spectroscopy were used to determine the ionization energy, thermal, and optical emission properties. A single level atEv+0.25 eV associated with Mn was observed. The photoionization threshold of the center is 1.12 eV.

ISSN:0021-8979    

DOI:10.1063/1.345079

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We report Hall‐effect results of controlled Hg‐diffusednregions on as‐grown,p‐type liquid‐phase epitaxial Hg0.8Cd0.2Te, for varying diffusion times. The Hall‐effect results of Hg diffusion through CdTe passivation layers of varying thickness for fixed time on as‐grownp‐type Hg0.8Cd0.2Te are also reported. From additional measurements of the electrical properties for then‐ andp‐type cases, the Hall data are analyzed in terms of the two‐layer model [R. L. Petritz, Phys. Rev.110, 1254 (1958)]. From this analysis, junction depth is estimated for a variety of experimental diffusion conditions using a fitting procedure in conjuction with a theoretical transport model. The fitting procedure results are verified by differential Hall measurements and also compared to diffusion theory [R. B. Allen, H. Bernstein, and A. D. Kurtz, J. Appl. Phys.31, 334 (1960)]. The sensitivity of determining junction depth to errors in estimates of the donor and acceptor concentration, and mobility within each layer, are discussed.

ISSN:0021-8979    

DOI:10.1063/1.345080

出版商:AIP    

年代:1990

数据来源: AIP