摘要:

The reflection high‐energy electron diffraction (RHEED) intensity level behavior during the growth of AlxGa1−xAs/GaAs quantum wells (QWs) is compared to the photoluminescence characteristics. The correlation between a decrease of the RHEED intensity level and the linewidth broadening of the excitonic QW transitions allows the unambiguous association of such a decrease with a roughening of the growth interface.

ISSN:0003-6951    

DOI:10.1063/1.102840

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Electron emitters in vacuum microelectronic devices need sharp tips in order to permit electron emission at moderate voltages. A method has been found for preparing uniform silicon tips with a radius of curvature less than 1 nm. These tips are formed by oxidation of 5‐&mgr;m‐high silicon cones through exploitation of a known oxidation inhibition of silicon at regions of high curvature.

ISSN:0003-6951    

DOI:10.1063/1.102841

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Undoped GaSb crystals with mirror‐like surfaces were obtained by liquid phase epitaxy from Sb‐rich solutions. The background carrier concentration strongly depended on the growth temperature. By growing crystals below 600 °C, we can obtain a GaSb crystal with a background carrier concentration under 1016cm−3. Photoluminescence studies showed that native defects related to Sb vacancies were significantly reduced in the GaSb crystal.

ISSN:0003-6951    

DOI:10.1063/1.102842

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We have studied the effects of ion implanting boron into glow discharge deposited hydrogenated amorphous silicon films (a‐Si:H). Electrical activity more than two orders of magnitude higher than previously reported1is measured in our samples. Implantations of Si ions are used to study the effect of post‐annealing on the radiation damage. Hydrogen introduced by low‐energy implantation and diffusion is found to completely recover electrical and optical characteristics in Si‐implanted specimens even at the highest concentrations (1021/cm3), where annealing for 1 h at 260 °C was insufficient. Introduction of H in B‐implanted samples was found to deactivate the boron, which can be reactivated by low‐temperature annealing.

ISSN:0003-6951    

DOI:10.1063/1.102843

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

GaAs/Ge/GaAs heterostructures have been grown by molecular beam epitaxy on GaAs substrates with nominally (100) and (100) tilted 4° towards [01¯1] orientations. High‐energy electron diffraction is used to study the antiphase boundaries of the GaAs grown on epitaxial Ge. We have observed the annihilation of GaAs antiphase boundaries on Ge grown on (100) GaAs substrates. GaAs on Ge grown on tilted substrates is observed to be free of antiphase domains.

ISSN:0003-6951    

DOI:10.1063/1.102818

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Rapid isothermal processing based on incoherent sources of light is emerging as a reduced thermal budget processing technique for the fabrication of next generation of semiconductor devices and circuits. In this letter, we show that integration of the rapid isothermal processing unit and the ultrahigh vacuum deposition system provides aninsiturapid isothermal processing capability for the solid phase epitaxial growth of SrF2and BaF2films on (100) and (111)InP. We also show that neither as‐deposited norexsituannealed films show solid phase epitaxial growth.

ISSN:0003-6951    

DOI:10.1063/1.103283

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The hot‐carrier immunity of submicrometer (0.8 &mgr;m)n‐channel metal‐oxide‐semiconductor field‐effect transistors with thin (∼8.6 nm) oxynitride gate dielectrics prepared by rapid thermal reoxidation (RTO) of rapidly thermal nitrided (RTN) SiO2has been studied. The hot‐carrier immunity was evaluated in terms of hot‐carrier‐induced transconductance degradation (&Dgr;Gm/Gm0) and interface state generation (&Dgr;Dit/Dit0) which was measured by using charge pumping current (Icp) measurement. It is found that for improved device performance and reliability, there exists an optimum RTO condition for a given RTN SiO2. In addition, a strong correlation between &Dgr;Dit/Dit0and &Dgr;Gm/Gm0has been observed.

ISSN:0003-6951    

DOI:10.1063/1.102819

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The coefficient of rectification,arect(&ohgr;), for a resonant tunneling diode is obtained from an exact solution for the transmission probabilityT(&egr;) through an oscillating resonant level. The experimentally observed broadening and lowering of the peaks inarect(&ohgr;) with increasing frequency &ohgr; are explained by the increase in spacing between the sidebands inT(&egr;). Most important,arect(&ohgr;) is entirely determined by the dc current. Consequently, any mechanism which broadens the negative differential conductance region will cause a dc‐like coefficient of rectification to persist to frequencies higher than the inverse charge‐transport time.

ISSN:0003-6951    

DOI:10.1063/1.102820

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Negative differential conductance (NDC) at 300 K inn+‐nn+‐GaAs/AlAs superlattice structures biased perpendicularly to the layers is demonstrated, and shown to be strongly enhanced at microwave frequencies close to the inverse transit time of electrons. The deduced electron velocities are in fair agreement with those independently determined in undoped superlattices where NDC was inhibited by the electric field nonuniformity. From the analysis of the experimental data, we show that NDC is a bulk superlattice effect, not related to ‘‘quantum defects,’’ e.g., enlarged barriers.

ISSN:0003-6951    

DOI:10.1063/1.102821

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Electron transport longitudinal to hydrogenated amorphous silicon/silicon nitride (a‐Si:H/a‐SiNx:H) multilayer structures (superlattices) with various barrier layer thicknesses has been measured by the time‐of‐flight method. The barrier thickness dependence of the electron drift velocity supports a transport model based on tunnel hopping from well to well under the influence of frequent trapping events in each well. The applied voltage dependence of the drift velocity is significantly superlinear in contrast with a linear character in bulka‐Si:H samples. The occurrence of the superlinearity is discussed by considering the applied voltage dependence of various effects which limit the longitudinal electron transport in superlattice structures. The occurrence of the superlinearity is possibly dominated by the existence of continuous distribution of deep traps in the gap of well layers rather than the applied voltage dependence of the tunneling rate, taking into account various possible effects.

ISSN:0003-6951    

DOI:10.1063/1.103284

出版商:AIP    

年代:1990

数据来源: AIP