摘要:

Electron emission from ferroelectric thin films (≤1 &mgr;m thick) is demonstrated. In addition, electron energy distributions have been measured using an Auger electron spectrometer. The electron emission measurements were performed using ferroelectric cathodes based on this Pb(Zr0.53Ti0.47)O3(PZT) films and 80–110 &mgr;m Pb0.93La0.07(Z0.53Ti0.47)O3(PLZT) layered capacitors with Pt top and bottom electrodes. Current densities in the range of 0.5–1.5 mA/cm2were measured from the PLZT cathodes excited with 100–400 V pulses, which produced electrons of about 265 eV with a narrow energy distribution (full width at half‐maximum of about 30 eV). On the other hand, current densities in the range 0.07–0.15 &mgr;A/cm2were measured for thin film PZT‐based cathodes excited with pulses in the range 10–40 V. The initial results suggest that the electron emission current may depend, among other factors, on the thickness of the ferroelectric layer, the applied excitation voltage, and the interval between the polarizing and switching pulses. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113940

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A new method is described for calculating the rf voltage division between two plasma sheaths in the capacitively coupled asymmetric Gaseous Electronics Conference reference cell, where the effective area ratio of the electrodes is unknown. The rf voltage across the ground sheath is found to decrease with increasing total electrode rf voltage, indicating that the effective area of the ground electrode increases significantly. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113941

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A beam plasma was generated and exhausted into air by applying rf voltage to the atmospheric pressure argon flowing through a cylindrical gap between a needle cathode and a grounded cylindrical anode whose surface was covered with an insulator. This torch‐type plasma with gas and electron temperatures of 240 °C (44.2 meV) and 1.0 eV, respectively, has been verified to be useful for ashing a photoresist without using a pumping system. High rate (≥1.2 &mgr;m/min) photoresist ashing was achieved by using Ar plasma containing a small amount of oxygen. Also reported are optical emission analysis of plasma and analyses of ashed Si surface by scanning electron microscopy. Fourier transform infrared spectroscopy, electron microprobe analysis, and x‐ray photoelectron spectroscopy. The use of the Pt cathode was found to provide not only a better ashed surface but also a higher ashing rate than the use of the stainless‐steel cathode. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113942

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A simple metallic bonding structure, has been developed consisting of a pure metal Nb and an alloy containing Sn, which can be employed to bond a semiconducting laser device and/or a silicon integrated circuit die to a submount with Au–Sn solder. Differential scanning calorimetry, transmission electron microscopy, and scanning electron microscopy reveal that the Nb layer acts effectively both as an adhesion layer to SiO2and diamond submounts and as a perfect diffusion barrier against Au–Sn solder. The metallization structure shows no indication of dewetting of the Au–Sn solder. The excellent bonding characters have been attributed to the unique metallurgical properties of Nb. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113943

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Lateral patterning of arsenic precipitates in GaAs is reported. The positions of near‐surface precipitates in a GaAs layer grown by molecular beam epitaxy at low temperature are controlled by InGaAs stressors 45 nm in width covered by a SiO2film. The stressors form a surface grating which governs the precipitate position by modulating the strain in the GaAs near the surface. Electron microscopy clearly reveals the formation of precipitates about 15 nm in diameter aligned with the stressors at a depth of ∼50 nm. It is suggested that this capability to control the position of nanometer‐size metallic particles within a semiconductor could open up new possibilities for novel devices. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113944

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Epitaxial Ba0.5Sr0.5TiO3(BST) thin films were deposited on LaAlO3substrates with the conductive metallic oxide SrRuO3(SRO) as a bottom electrode by pulsed laser deposition. The BST and SRO films were (h00) and (00l) oriented normal to the substrate surface, respectively. The epitaxial nature of both BST and SRO layers was determined by the measurement of in‐plane orientation with respect to the major axes of the substrate. Ion beam channeling with a minimum yield of around 10% from Rutherford backscattering spectrometry demonstrated the films to be of high crystallinity. A dielectric constant around 500 and dielectric loss less than 0.01 at a frequency of 10 kHz were measured on the capacitors with a configuration of Ag/BST/SRO. Electrical measurements on such epitaxial BST films showed a breakdown voltage above 106V/cm and a leakage current density of less than 5×10−8 A/cm at a field intensity of 2×105V/cm. These results prove the BST/SRO heterostructure to be a good combination for microelectronic device applications. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113945

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Direct deposition of Mo microstructures on Si is demonstrated by photolytic decomposition of condensed Mo(CO)6using the aperture‐limited, high‐intensity radiation from an undulator at the BESSY storage ring. A particular advantage of the instrument, a new photon‐induced scanning Auger microscope, is the possibility of quasisimultaneous exposure (writing) and analysis employing photoemission (PES) or x‐ray induced Auger spectroscopy (XAES) with sufficient energy resolution for detection of chemical differences. The present spatial resolution is 20–30 &mgr;m (for PES and writing) and 3 &mgr;m (for XAES), but this will be improved by adding focusing mirrors. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113946

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Etching and homoepitaxial growth were performed on 0.1°, 3.5°, and 11.0° off (001) diamond substrates using microwave plasma‐assisted chemical vapor deposition. Etched surfaces showed a sequential morphological change from etch pits to stepped surface to flat surface with increasing misorientation angle. In homoepitaxial growth hillock formation on the (001) surface was ascribed to the lack of surface steps on the well‐oriented substrate, while the growth on the misoriented surfaces proceeded via step flow along ⟨110⟩. Reflection high‐energy electron diffraction showed that the films were single crystals and their surfaces were composed of the 2×1 and 1×2 double‐domain structure. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113947

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A polycrystalline silicon oxidation method, which considerably improves the surface roughness at the oxide/polycrystalline silicon interface, is presented. The surface roughness at the interface is observed by transmission electron microscopy and is also evaluated by atomic force microscopy after the oxide layer is removed using buffered HF acid. The oxide/polycrystalline silicon interface by the new oxidation method with the 50 A˚ thick intermediate oxide has the rms surface roughness of 30 A˚, while that of the interface by the conventional method is 120 A˚. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113948

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Extended x‐ray absorption fine structure (EXAFS) above the TaL3edge on tantalum oxide capacitor films has been measured. Tantalum oxide films were prepared by low‐pressure chemical vapor deposition (CVD) using a Ta(OC2H5)5and O2gas mixture. Four kinds of tantalum oxide films were studied: as‐deposited (amorphous), N2annealed (crystalline), dry O2annealed (crystalline), and O2‐plasma annealed (amorphous). From EXAFS analysis, differences in the local structures of tantalum oxide capacitor films, in terms of oxygen deficiency around Ta, were observed in the various annealed films. The leakage current characteristics of tantalum oxide capacitors correspond to the differences in the local structures around Ta. ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.113169

出版商:AIP    

年代:1995

数据来源: AIP