摘要:

BF2implantation is widely used to form P wells, adjust channel threshold voltage, and reduce short channel effects. In this letter, we study effect of BF2implantation on ultrathin gate oxide reliability. It has been found that BF2implantation into Si substrate causes degradation of gate oxide reliability in the ultrathin oxide thickness regime. N2O oxide can be used to reduce degradation caused by the implantation and improve gate oxide reliability. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117040

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Secondary electron (SE) image contrast fromp‐type silicon has been studied using field‐emission scanning electron microscopy (FE‐SEM). Cross‐sectional FE‐SEM images of boron‐doped silicon heterostructures have been compared with atomic concentration and free carrier profiles measured by secondary‐ion mass spectroscopy and electrochemical capacitance‐voltage profiling, respectively. FE‐SEM image contrast due to dopants has been shown to be electronic in origin. Since electrically active dopant species contribute solely to SE image contrast, FE‐SEM can be effectively used to map electrically active dopant profiles in two dimensions with a sensitivity as low as 1016cm−3. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117041

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Longitudinal optical (LO) phonon relaxation is investigated in a GaAs/AlGaAs triple barrier tunnel diode at strong perpendicular magnetic fields. We observe LO‐phonon assisted tunneling to the ground state as well as to Landau level states. Maxima in the LO‐phonon assisted tunnel peak are found each time the LO‐phonon energy matches multiple of the Landau level spacing. Corresponding maxima as well as parity effects are found in the integral tunnel conductance. The results indicate enhancement of LO‐phonon assisted inter Landau level transitions with increasing magnetic field. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117042

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Al/i:GaInP/n:GaAs Schottky structures of varying undoped layer thicknesses (100–1000 A˚) were growninsituby gas source molecular beam epitaxy (GSMBE). Effective Schottky barrier heights (&fgr;bIV)of 0.87±0.02 eV were determined from the current–voltage (I–V) method with ideality factor of <1.05 which is characteristic of thermionic emission but a decrease in barrier height (&fgr;bCV) with increasing GaInP thickness as measured by the capacitance–voltage (C–V) method was observed. We found that the plot of &fgr;bIVminus &fgr;bCVversus GaInP thickness is a straight line. This can be explained by modeling a positive delta sheet charge at the GaInP/GaAs interface which will result in a constant electric field (slope of the above line) with sheet charge estimated to be 5×1011cm−2. This sheet charge is proposed to be the result of ionized donor states at such interface. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117043

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We have studied the influence of misfit dislocations on hole accumulation in the base layer of ann‐AlGaAs/p‐GaAs/n‐InGaAs heterojunction phototransistor (HPT). Spatially and temporally resolved cathodoluminescence (CL) measurements reveal that variations in the hole accumulation is caused primarily by strain‐induced defects which impede the transport of holes in the collector. The lifetime of holes in the InGaAs/GaAs collector is found to be negligibly affected by the underlying misfit dislocations in the InGaAs/GaAs collector. The reduction in the local electron‐beam‐induced current signal by the dislocations is less than ∼20%, indicating that these defects have a minor impact on the overall device performance. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117044

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We have investigated the low energy electron beam irradiation (LEEBI) annealing kinetics of Mg‐doped GaN films grown by metalorganic chemical vapor deposition. Our results show that LEEBI annealing at room temperature, monitored by cathodoluminescence spectroscopy as a function of irradiation time, occurs rapidly initially and then proceeds gradually until saturation. We have also demonstrated that LEEBI annealing is effective even at liquid helium temperature, indicating its athermal mechanism. Our observations support the dynamic model involving electronically stimulated dissociation of Mg–H bonds and the escaping and retrapping of atomic hydrogens. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117045

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We report the successful fabrication of flexible single crystal semiconductor structures. A highly selective etching solution allowed us to obtain large area foils and membranes of good structural integrity, using films of indium and silicone as flexible substrates. Photoluminescence and transmission measurements verified that the optical properties of these structures were preserved. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117046

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Electron injecting electrodes made of magnesium and silver alloys (Mg:Ag) with a wide range of Ag concentration from 0 to 26.6 at. % were successfully fabricated for organic light‐emitting diodes (LEDs) by using the radio frequency sputter deposition technique. The LED characteristics such as intensity, turn‐on voltage, and durability of electroluminescence were strongly dependent on the Mg:Ag composition. Both the work function and the structural order of these Mg:Ag electrodes played a crucial role in determining the LED characteristics. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117047

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Photoluminescence has been measured for double‐ and separate‐confinement InAsSb/InAsSbP heterostructures grown by low‐pressure metalorganic vapor deposition. A measurement of the integrated luminescence intensity at the temperature range of 77–300 K shows that over a wide range of excitation level (1–5×102W/cm2) the radiative transitions are the dominant mechanism belowT∼170 K. Auger recombination coefficientC=C0 exp(−Ea/kT) withC0≊5×10−27cm6/s andEa≊40 meV has been estimated. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117048

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We have designed a simple‐hot wall low pressure chemical vapor deposition (LPCVD) system to grow high quality epitaxial Si films from 550 to 900 °C. The epitaxial film has been examined by scan electron microscopy for surface morphology, and by x‐ray diffraction and cross‐sectional transmission electron microscopy for crystallinity. Its quality has been found comparable to that of the substrate. Reduction of moisture and oxygen in the ambient is critical to the success of the growth at low temperatures. A combination of a leak‐tight LPCVD reactor, a high flow rate of 61/min of H2purge, and a pre‐bake at high temperature of 950 °C has been used to achieve the reduction of moisture and oxygen. Degraded films form with increasing full width at half maximum of x‐ray diffraction peak when a pre‐bake at lower temperature is used. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117049

出版商:AIP    

年代:1996

数据来源: AIP