摘要:

Surface nitridation of thin SiO2films (130 A˚) has been achieved in low ammonia pressures (P≤10−1mbar) by thermal activation (900 °C≤T≤1050 °C) or by electron‐beam‐enhanced reaction at room temperature. In the first case, the nitridation rate increases withP,T, and timet; in the latter, it depends onP,t, electron energy and flux, and reaches a maximum within the energy range (1–∼1.7 keV). Electrical characterization of metal‐insulator‐semiconductor structures shows that the SiO2/Si interfacial quality is not damaged as long as interfacial nitrogen concentration remains negligible. However, bulk and/or interfacial fixed positive charges are detected in the SiO2films nitrided at room temperature.

ISSN:0003-6951    

DOI:10.1063/1.97651

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Single‐crystal CoSi2films have been grown in solid phase epitaxy regime under nonultrahigh vacuum conditions on (111) Si by electron gun deposition of Co thin films followed by rapid thermal annealing in Ar ambient. The single‐crystal films were analyzed by transmission electron microscopy to share the (111) Si surface normal but are rotated 180° about that axis with respect to the substrate. The effect of gas ambient was found to be of critical importance in the growth of single‐crystal CoSi2on (111) Si. The present nonultrahigh vacuum treatments to grow single‐crystal films on silicon shall greatly facilitate the fabrication of novel classes of high‐speed and high‐frequency devices employing buried silicide layers.

ISSN:0003-6951    

DOI:10.1063/1.97652

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The effect of thin titanium carbide layer on the ion beam mixing of Ni and Si was studied. No mixing was observed following the ion beam bombardment at 600 keV to the fluence of 8×1015Xe++/cm2. Furthermore, it was also found that Ti and C layers alone could prevent an ion beam mixing between Ni and Si, although in the Ti case mixing did occur between Ti and Ni. These results were compared to a thermodynamic model of ion mixing and found to be in qualitative agreement but relative quantitative agreement was poor.

ISSN:0003-6951    

DOI:10.1063/1.97653

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Hydrogenation of the boron acceptor in silicon is observed during Fowler–Nordheim tunneling injection of electrons for the first time. Experiment is also presented which shows that the existence of free holes at the silicon surface is not important for boron hydrogenation.

ISSN:0003-6951    

DOI:10.1063/1.97654

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We have observed optical transitions between the first subbands of the conduction band and the split‐off valence band in GaSb/AlSb quantum well structures. The well width dependence of the emission energies is traced to quantization in the conduction band and in the split‐off band. By comparison with data for the band‐edge transitions the effective &Dgr;0gaps is the quantum wells are determined. Contrary to previous calculations the &Dgr;0gap energies are almost independent of the well width.

ISSN:0003-6951    

DOI:10.1063/1.97655

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The degradation of hydrogenated amorphous silicon under an applied field is studied in an amorphous silicon thin‐film transistor. A possible mechanism for metastable defect creation due to trapping of electrons at weak bonds together with a bond‐switching event is investigated. The energy for the bond‐switching process is assumed to be supplied thermally. The rate equation is set up and it is shown that this new model for defect creation is capable of describing the experimentally observed slow field‐effect current transients at various temperatures.

ISSN:0003-6951    

DOI:10.1063/1.97656

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Depth profiles of various constituents and impurities of thin films were obtained simultaneously by a nuclear coincidence method. The energy spectrum of elastically scattered 12 MeV protons, measured by a high‐resolution magnetic spectrometer, was used for constituent identification and total content determination. Constituents of interest were selected by software pulse height discrimination and their depth profiles were obtained from the recoil energy spectrum, measured by a surface barrier detector telescope. Thin films of Teflon, of carbon, and of amorphous hydrogenated silicon were measured. The best possible depth resolution is about 20 nm for carbon and is limited by the beam energy spread and the energy resolution of the solid state detectors.

ISSN:0003-6951    

DOI:10.1063/1.97657

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The effects of the predominant residual impurity boron on the electrical properties of In‐doped, dislocation‐free, semi‐insulating GaAs crystals are investigated. Crystals are grown from various arsenic‐rich melts using the vertical magnetic field applied, fully encapsulated Czochralski technique. It is found that carrier and neutral EL2 concentrations in as‐grown crystal and sheet carrier concentration in the Si‐implanted active layer decrease as the boron concentration increases. The effect of boron decreases as the melt composition becomes more arsenic rich. The results suggest that boron decreases the Ga vacancy concentration.

ISSN:0003-6951    

DOI:10.1063/1.97658

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The role of the relative surface kinetics of Ga and Al in determining the nature of normal and inverted interfaces defining GaAs/Al0.3Ga0.7As thin single quantum well (SQW) structures is examined via photoluminescence and excitation spectra studies on SQW structures grown under conditions determined by reflection high‐energy electron diffraction intensity dynamics to shed specific light on this issue. Results are found to be in conformity with the role of surface kinetics exemplified by computer simulations of growth and underscore the critical importance of controlling both the structural and chemical nature of interfaces via choice of optimized growth conditions.

ISSN:0003-6951    

DOI:10.1063/1.97659

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We discuss a new low‐pressure and low‐temperature process for the chemical vapor deposition (CVD) of silicon dioxide. The process differs from conventional low‐pressure CVD in that lower temperatures (150–300 °C) and a unique pressure window (2–10 Torr) provide the conditions for the reaction of silane (SiH4) and oxygen. In this thermal process, activation energies of 0.15–0.18 eV and deposition rates of 100 A˚/min at 250 °C are achieved. This technique is approximately 15 times less sensitive to the O2:SiH4ratio than atmospheric pressure CVD. The deposition conditions are compatible with both low‐temperature silicon and III‐V technologies. Preliminary current‐voltage and capacitance‐voltage measurements on Si indicate dielectric field strength of 3–8×106V/cm and fixed oxide charge density (Qss) less than 1011cm−2.

ISSN:0003-6951    

DOI:10.1063/1.97660

出版商:AIP    

年代:1987

数据来源: AIP