摘要:

The first example of a recombination enhanced defect reaction in InP is reported. The major defectE(0.79 eV) introduced by 1‐MeV electron irradiation ofp+njunctions, formed by Zn‐doped epilayers on undopedn‐type substrates, is not observed with Schottky barrier structures on similar material. The defect exhibits a reduction in activation energy of recovery from 1.3 eV under pure thermal annealing to 0.42 eV with minority‐carrier (hole) injection. The enhanced reaction rate is proportional to the square of the injected current showing that the process results from two particle capture.

ISSN:0003-6951    

DOI:10.1063/1.95282

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

From a study of the effect of light exposure on photoconductivity and solar cell performance of hydrogenated amorphous silicon alloys for different exposure time and intensity, we show that the light‐induced changes do not obey reciprocity. Degradation is larger at high intensity light exposure for a shorter time than at low intensity exposure for a longer time even though the product of the exposure time and light intensity is kept a constant. A model that can explain the failure of reciprocity is discussed.

ISSN:0003-6951    

DOI:10.1063/1.95283

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Comparisons were made between (Al‐1% Si)/n+Si contacts in which the phosphorus dopant had been implanted through native‐oxide or grown‐oxide layers, and similar contacts in which the phosphorus dopant had been implanted through a ∼300‐A˚ Al layer. The Al layer was flash evaporated immediately afterinsituplasma cleaning to remove the native oxide from the silicon, thereby minimizing the incidence of oxygen ‘‘knock‐on’’ during implantation. Pre‐alloy and post‐alloy contact resistance measurements showed the contacts implanted through Al to be more responsive to the metal alloying process and to have significantly lower post‐alloy contact resistances than contacts implanted through either native‐oxide or grown‐oxide layers.

ISSN:0003-6951    

DOI:10.1063/1.95284

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We have calculated the concentrationnsoof the two‐dimensional gas in the AlGaAs/GaAs modulation‐doped structures with graded heterointerfaces. Our calculation shows thatnsoincreases with the increase in the grading lengthWGRat small values ofWGR. Depending on composition and doping of the AlGaAs layer the maximum value ofnsois achieved forWGRbetween 20 and 70 A˚. An increase in the concentration of the 2‐d gas leads to a larger device transconductance and to a large current swing. Hence, the device performance may be improved by grading the heterointerface.

ISSN:0003-6951    

DOI:10.1063/1.95285

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

By solving Poisson’s equation in dark and light, it is concluded that the observed surface photovoltage in hydrogenated amorphous silicon necessarily involves a transfer of charge between the surface states and the space‐charge region, and does not directly give the band bending. Experimental evidence which supports this conclusion is presented.

ISSN:0003-6951    

DOI:10.1063/1.95286

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A new procedure for thermal nitridation of silicon is reported. Active nitrogen generated using a microwave discharge is passed over silicon wafers in an externally heated quartz tube at low pressure (0.3 Torr). Nitridation is shown to be significantly enhanced by the addition of small amounts (20–200 ppm) of SF6to the nitrogen before it enters the discharge. In this way films about 100 A˚ thick with a refractive index of 2.0±0.06 can be grown at 1050 °C in 4 h. The films have etch rates of 10–15 A˚/min in buffered HF (NH4F:HF=7:1). Auger analysis shows [N]/[O] atomic ratios of about 2. A 60‐A˚ film grown at 1000 °C inhibited substrate oxidation for over 16 h in dry oxygen at 1000 °C.

ISSN:0003-6951    

DOI:10.1063/1.95287

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A calculation of the phonon‐limited mobility of electrons confined to the channel of a GaAlAs/GaAs heterostructure has been performed with full account of the quasi‐two‐dimensionality of the channel. At 77 K the results show a reduction of mobility of about 25% as electron density increases from threshold to 7×1011cm−2; at room temperature the mobility of pure bulk GaAs is found almost independent of confinement.

ISSN:0003-6951    

DOI:10.1063/1.95288

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Superconducting accelerating cavities made of Nb‐coated copper were produced. Niobium films of a thickness ranging from 1.4 to 4 &mgr;m were deposited onto the inside of 3‐GHz cavities and 500‐MHz frequency by bias diode sputtering. A maximum accelerating field of 8.6 MV m−1was reached without quench which is attributed to the large thermal conductivity of copper at liquid helium temperatures.

ISSN:0003-6951    

DOI:10.1063/1.95289

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Magnetic domain structure on a silicon iron (001) surface has been observed using a new scanning electron microscope (SEM), in which image contrast was obtained by using spin polarization of secondary electrons. From this image and an absorption current image of the same area, it has been confirmed that the domain structure image is not influenced by surface morphology. This represents an improvement over conventional domain structure observation methods. This new SEM will be greatly improved also as for the resolving power compared to conventional reflection methods, when used in conjunction with a proper field emission gun.

ISSN:0003-6951    

DOI:10.1063/1.95290

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A model for the origin of asymmetric dielectric relaxation in dipolar materials is proposed through a Monte Carlo study. The principal shortcomings of the Debye approach with a distribution of relaxation times can be overcome.

ISSN:0003-6951    

DOI:10.1063/1.95291

出版商:AIP    

年代:1984

数据来源: AIP