摘要:

The ordered structure occurring in AlGaInP quaternary alloys grown on GaAs substrates by low‐pressure metalorganic vapor phase epitaxy has been investigated by means of x‐ray diffraction measurements. The order spot became strong as the Al content increased, and was observed only for the (1/2 ∼(1/2) 1/2) diffraction, corresponding to CuPt‐type (111)Bordering. Kinematical analysis implies that the full width at half maximum of the order spot is strongly affected by the antiphase boundary, whereas the integrated intensity is not.

ISSN:0003-6951    

DOI:10.1063/1.102057

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The oxide traps created by hot‐hole injection in the thin gate oxide ofn‐type metal‐oxide‐semiconductor transistor are optically and electrically characterized. Photodepopulation spectroscopy is used to investigate their photodetrapping kinetics. A threshold at 3 eV is found for the photoionization cross section. The effect of the electric field on the emission is analyzed using the Poole–Frenkel model. We show that a localized energy level in the range 2–3 eV below the SiO2conduction band is associated with trap. It is spatially localized above the drain region of the transistor.

ISSN:0003-6951    

DOI:10.1063/1.102058

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We have investigated the energy dependence and depth distribution of the damage caused by ion beam etching using Ar/O2−ions with energies in the range between 175 and 1200 eV. The damage was created by partially etching the upper InP barrier of In0.53Ga0.47As single quantum wells. The optical emission from the quantum wells is used as a high‐resolution local probe for the damage. From the decay of the quantum efficiency as a function of the etch depth we determine an effective damage range of about 8.4 nm for 250 eV ions in InP.

ISSN:0003-6951    

DOI:10.1063/1.102059

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Infrared absorption at oblique incidence and Raman scattering were used to measure plasmon spectra in highly dopedn‐type GaAs layers grown by molecular beam epitaxy. Plasmon frequency was lower in infrared absorption spectra compared to Raman spectra of the same samples due to the wave vector dependence of the plasmon frequency. The linewidth of plasmon lines was quite similar in infrared absorption and Raman scattering spectra, indicating the small role of Landau damping for the studied range of wave vectors. Infrared plasmon absorption was strongly reduced for films thicker than the wavelength of plasmons, and the wave vector dependence was reduced for very thin films when the electron gas started to acquire quasi‐two‐dimensional character.

ISSN:0003-6951    

DOI:10.1063/1.102060

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The effect of coincident ion bombardment on the oxidation of Si (100) by atomic oxygen has been examined under ultrahigh vacuum conditions by employing molecular beam techniques and x‐ray photoelectron spectroscopy. Ion bombardment leads to a significant enhancement in the rate of oxidation. By modulating both the oxygen and ion (Ar+) fluxes several possible mechanisms for the enhanced rate can be eliminated. Of the remaining possibilities, a mechanism involving competition between ion‐induced oxygen incorporation and sputtering appears most likely.

ISSN:0003-6951    

DOI:10.1063/1.102352

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A novel technique for Si epitaxial lateral overgrowth, called tunnel epitaxy, is proposed and demonstrated. In this technique, lateral epitaxy proceeds in the tunnel between the upper and lower SiO2layers. Limitation of film thickness is achieved, as is a high lateral/vertical growth ratio of approximately 7. Lateral growth distance is limited by clogging of the gas injection window by polycrystalline Si grain growth. Rough surface morphology and twin boundary defects were observed in the fabricated silicon‐on‐insulator. The origins of and possible solutions for these problems are discussed.

ISSN:0003-6951    

DOI:10.1063/1.102061

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We report the preparation of InGaAs/AlGaAs strained‐layer(pseudomorphic) modulation‐doped field‐effect transistor (MODFET) structures by organometallic vapor phase epitaxy (OMVPE). Devices fabricated from these structures with 0.9 &mgr;m gate lengths had dc extrinsic transconductances up to 340 mS/mm. Microwave testing up to 40 GHz showed current gain cutoff frequencies ( fT) of 22 GHz and estimated maximum frequency of oscillation ( fmax) of 70 GHz. This is the first report to our knowledge of the use of OMVPE material in the fabrication of pseudomorphic MODFETs.

ISSN:0003-6951    

DOI:10.1063/1.102062

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We report a first determination of the conduction‐band offset in the strained‐layer Al0.15Ga0.85As/In0.15Ga0.85As/GaAs pseudomorphic structure. Two‐dimensional electron density and its effective mass are independently measured by Shubnikov–de Haas and cyclotron resonance experiments for a series of samples with a range of spacer thickness from 30 to 100 A˚. Using a charge transfer model, the conduction‐band offset at the Al0.15Ga0.85As/In0.15Ga0.85As interface is found to be (255±35) meV.

ISSN:0003-6951    

DOI:10.1063/1.102063

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The electrical characteristics of regrown interfaces deposited using an alternate metalorganic chemistry, diethylgallium chloride (DEGaCl), are investigated. With the appropriate HCl pre‐regrowth surface treatment, these interfaces are found to be of very high quality with no substantial interface charge. The contact resistivity, as determined by transmission line measurements, is (2–4)×10−7&OHgr; cm2at both 77 and 300 K. Secondary‐ion mass spectroscopy measurements show no detectable accumulation of impurities at the regrown interface, in contrast to those regrown using the conventional trimethylgallium‐based chemistry.

ISSN:0003-6951    

DOI:10.1063/1.102064

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A quantitative theoretical model for bulk 1/fnoise in semiconductor resistors has been developed. The model uses the fact that random fluctuations of the steady‐state deep level trapped electron density at some point in a depletion layer decay exponentially with a time constant which depends on the local free‐electron density. The model was used to derive an exact integral expression and a simple approximate analytic expression for the spectral density of bulk 1/fand generation noise in unsaturated field‐effect transistors. Excellent agreement with experimental results is obtained. The relationship between bulk 1/fand generation noise spectra is discussed.

ISSN:0003-6951    

DOI:10.1063/1.102065

出版商:AIP    

年代:1989

数据来源: AIP