摘要:

A new method for the direct determination of minority‐carrier lifetime is presented, which utilizes transient capacitance measurements performed with varying depletion voltages on metal‐oxide‐semiconductor (MOS) structures. It is shown that the slope of the fill (storage) time versus the depletion voltage is directly proportional to the minority‐carrier lifetime. Good agreement is shown between results obtained with the proposed method and those obtained using a standard technique. The method is limited, however, to low‐doped MOS structures which can be depleted to the back contact.

ISSN:0003-6951    

DOI:10.1063/1.95008

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Femtosecond intraband relaxation dynamics of hot carriers in highly excited states of GaAs, AlGaAs, and AlGaAs/GaAs multiple quantum well (MQW) structures are studied at room temperature using the equal‐pulse correlation technique. Initial carrier lifetimes of 35, 60, and 50 fs are measured for GaAs, Al0.32Ga0.68As, and MQW structures for excitation with 2.02‐eV photons at low carrier densities, and are in reasonable agreement with calculated scattering rates. The carrier‐density dependence of these lifetimes is measured for densities in the range 1.5×1017–5×1019cm−3.

ISSN:0003-6951    

DOI:10.1063/1.94984

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The effects of implantation temperature (Ti) on the chemical and physical structure of annealed high‐dose oxygen ion implanted layers were investigated by Auger electron spectroscopy (AES) and transmission electron microscopy (TEM). At lowTi(∼400 °C) the buried oxide is bordered by layers of polycrystalline silicon (polysilicon) which, in the top silicon layer, is separated from damaged single crystal Si by a thin band of discontinuous oxide. These polysilicon layers are formed from amorphous regions during high‐temperature anneals. At highTi(∼500 °C) polysilicon was not observed.

ISSN:0003-6951    

DOI:10.1063/1.95009

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Efficient radiative defects are introduced in silicon by annealing at 450 °C. They are associated with very sharp and intense transitions at 0.926 eV (Hline) and at 0.767 eV (Pline). A close correlation has been established between the intensity of these lines and the oxygen content of the sample. The carbon content correlates also with the lineH. It is shown that the radiation induced lines at 0.79 eV (Cline) and at 0.97 eV (Gline) are similarly influenced by the oxygen and carbon content. Although the detailed nature of the centers responsible forHandPlines is not known it can be put forward that their formation is controlled by Oimigration, and that the center leading toHmust be similar to theGcenter (CSi–Sii−CSi).

ISSN:0003-6951    

DOI:10.1063/1.95011

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We have found that a thin silicon dioxide skin stabilizes the float zone in ribbon‐to‐ribbon single crystal growth. 40‐&mgr;m‐thick single crystal ribbons, oriented ⟨100⟩ and scanned in the ⟨011⟩ direction, were grown completely free of subgrain as well as grain boundaries. This surprising suppression of low angle grain boundaries may be related to a similar effect which has been seen in supported thick silicon on SiO2films.

ISSN:0003-6951    

DOI:10.1063/1.95012

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Characterization of semi‐insulating liquid encapsulated Czochralski GaAs by cathodoluminescence in a scanning electron microscope at liquid He temperatures has revealed that the main residual impurity, carbon, is not distributed homogeneously within the material. This may lead to nonuniformities in the electrical properties of the material.

ISSN:0003-6951    

DOI:10.1063/1.95013

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Photocapacitance transients due to photoquenching have been measured to characterize midgap electron traps (the ‘‘EL2 family’’) in different GaAs wafers. The spectral distributions of photoquenching rates in liquid encapsulated Czochralski, vapor phase epitaxial, and oxygen‐implanted liquid phase epitaxial GaAs were different to each other and also different from that in horizontal Bridgman‐grown GaAs. From these results it is suggested that the EL2 family has multimetastable states and may consist of arsenic‐atom aggregates.

ISSN:0003-6951    

DOI:10.1063/1.94972

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Electrical properties of 3C‐SiC layers, epitaxially grown on silicon by chemical vapor deposition, have been investigated at the temperatures between room temperature and 850 °C. In this temperature range, the electron mobility changes with temperature as &mgr;H∼T−1.2∼−1.4. The weaker temperature dependence of mobility and the larger mobilities compared with other polytypes of SiC suggest that 3C‐SiC is a promising material for devices operated at high temperatures.

ISSN:0003-6951    

DOI:10.1063/1.94973

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We propose a new trilayer resist system (photoresist/As2S3/polymethyl methacrylate) using spin‐coated As2S3(0.20  &mgr;m thick) as a barrier layer. As2S3has shown high etch rate (more than 30 times) in SF6+4% O2reactive ion etching compared to organic photoresists which allows a precise pattern transfer. The spin coating process of As2S3is compatible with conventional processing. As2S3has high absorption coefficient in ultraviolet and deep UV eliminating substrate reflection. Patterns of micron and submicron dimensions were replicated successfully.

ISSN:0003-6951    

DOI:10.1063/1.94974

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The electrical properties and distribution of impurities in As+‐ and BF+2‐implanted Si activated using rapid thermal annealing (RTA) are discussed. Sheet mobility and activation of the implanted Si ⟨100⟩ samples (As+: 60 keV, 1×1015cm−2and BF+2: 45 keV, 1×1015cm−2) as functions of annealing temperature are reported for RTA. Secondary ion mass spectroscopy atomic profiles of samples preannealed at 600 °C in furnace, followed by RTA are presented. Full electrical activation of As occurs at 1100 °C and that for B (BF2) occurs at 950 °C. A 600 °C, 1‐h furnace preanneal does not have any noticeable effect on reducing the dopant redistribution during 2‐s, 1170 °C RTA for 1×1015cm−2As+implants and during 2‐s, 1100 °C RTA for 1×1015cm−2BF+2implants. This lack of ‘‘diffusion difference’’ is attributed to the high RTA temperatures at which mechanisms other than the point defects caused early time enhanced diffusion play a dominant role in impurity redistribution.

ISSN:0003-6951    

DOI:10.1063/1.94975

出版商:AIP    

年代:1984

数据来源: AIP