摘要:

Sputtering yields of metal ion beams on polycrystalline films for energies below 1 keV were measuredin situusing crystal microbalance techniques. Self‐sputtering yields were determined for Au, Cu, Ag, Cr, and Al for energies from 10 to 500 eV. These yields were consistent with some previous noble‐gas sputtering yields when only the difference in ionic mass was taken into account. Residual oxygen significantly lowered the self‐sputtering yields of Al and Cr for all energies from 0 to 1 keV and the collection rate of oxygen was apparently greater for ions of about 10 eV. Sputtering yields of films by dissimilar metal ions were most strongly influenced by the type of metal in the beam, rather than by the target material, even for high ion energies.

ISSN:0021-8979    

DOI:10.1063/1.1658100

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

An ac test method is described which allows separation of contact influences from the bulk resistance of semiconductors and the measurement of their properties simultaneously. As an example, this method is applied to thin CdS films with different metal electrodes. Examples are given for the light and voltage dependence of both bulk and contact resistance, the true rise and decay curves, and the separation of changes in contact and bulk resistance with time or by post deposition treatments.

ISSN:0021-8979    

DOI:10.1063/1.1658101

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The Hall effect in trigonal selenium single crystals has been measured by a dc method. The measurements give a carrier concentration of 0.5×1015cm−3at room temperature and 1015cm−3at 100°K. The conductivity is ofptype within the entire temperature range. By illumination with extrinsic light the carrier concentration has to a certain extent turned out to be independent of the intensity of light. The mobility calculated from a barrier model is about 260 cm2/V sec at room temperature in the direction of thecaxis. The value is considerably higher than earlier reported values.

ISSN:0021-8979    

DOI:10.1063/1.1658102

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The chemical polishing of the anion face of ZnO, ZnS, CdSe, and ZnTe and the cation face of CdSe and ZnTe with bromine dissolved in methanol has been accomplished. The etch rates of the bromine‐methanol solution on the anion and cation faces of BeO, ZnO, ZnS, CdS, CdSe, ZnTe, and InSb have been measured at room temperature. An empirical relationship between the etch rates of the bromine‐methanol solution and the difference of the electronegativity of the component elements has been found.

ISSN:0021-8979    

DOI:10.1063/1.1658103

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A very nonuniform copper distribution occurs in and near a gallium‐diffused layer in germanium. This gives rise to ap+‐&pgr;‐pstructure, the presence of which has been detected using the sign reversal of the contact photovoltaic effect at wavelength near the absorption edge. Using64Cu and radiochemical techniques, it has been demonstrated that a high concentration of copper collects in a diffused layer and leads to the observed contact structure.

ISSN:0021-8979    

DOI:10.1063/1.1658104

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Measurements of electrical properties of ann‐type inversion layer at the surface of ap‐type InSb at low temperatures are reported. The surface inversion layer was produced by the application of the electric field normal to the surface of InSb in a metal‐oxide—p‐InSb structure. The observed field effect mobility shows that the motion of the electrons in the surface inversion layer is quantized in one direction and of two‐dimensional nature. Information for the trapping state in the oxide was obtained. A new type of current‐voltage characteristic, which is supposed to originate in the electron transfer from the lower quantum level to the higher one, was also observed.

ISSN:0021-8979    

DOI:10.1063/1.1658105

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The resistivity and Hall coefficientRHfor Zn‐doped GaP were measured at temperatures between 4.2° and 775°K. Neutron activation and through diffusion with radioactive65Zn were used to determine the Zn concentrationNZn, which ranged from 6.7×1016cm−3to 2.1×1019cm−3. At the lowest Zn concentration the thermal ionization energy for Zn in GaP was found to be 0.060±0.002 eV. The thermal ionization energy decreases rapidly for Zn concentrations in excess of 2.0×1017cm−3. Metallic impurity conduction was observed at a Zn concentration of 2.1×1019cm−3. The low‐concentration region is observed forNZn≲2.0×1017 cm−3, the intermediate‐concentration region for2.0×1017≲NZn≲2.1×1019 cm−3, and the high‐concentration region forNZn≳2.1×1019 cm−3. In the intermediate‐concentration region the high‐temperature hole concentration, determined fromp=1/eRH, was found to exceed the Zn concentration by a significant amount. Analysis of the temperature‐dependent hole concentration results in an effective density‐of‐states mass ratio of approximately 0.5. The lightest doped sample had a room‐temperature Hall mobility of 120 cm2/V·sec and a maximum mobility of 2050 cm2/V·sec at 55°K. The maximum mobility at low temperature is limited by ionized and neutral impurity scattering, while the dominant high‐temperature scattering mechanism appears to be optical phonon scattering.

ISSN:0021-8979    

DOI:10.1063/1.1658106

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The deposition of thin silicon films by the electron beam dissociation of adsorbed tetramethylsilane has been investigated. Growth rate was studied as a function ofPthe vapor pressure of tetramethylsilane,Tthe substrate temperature, andJthe current density. It was found that there is a region where the value of the growth rate can be calculated from the expressionr=KPJexpa/T, whereKandaare constants. Assuming a model in whicha=Q/RandK=c&sgr;, whereRis the gas constant andcis a calculable constant,Q, the heat of adsorption, was found to be 11.6 kcal/mole and &sgr;, the collision cross section, was determined to have the unexpectedly high value of 3.86×103Å2for 300‐V electrons. Electron diffraction and transmission electron microscopy showed the as‐deposited films to be amorphous. The resistivity of these films varied with thickness and showed a minimum value of approximately 5×104&OHgr;·cm when the film thickness was between 1000 and 1500 Å. Thinner films were less conductive because the high amount of stress in the film increased scattering. Thicker films were less conductive because the impurity content of the films increased with film thickness. Heat treating at 800°C produced extensive grain growth and resistivities dropped by a factor of 103. Annealing at 300°C for a few hours decreased the resistivity by about a factor of two although no grain growth occurred at this temperature.

ISSN:0021-8979    

DOI:10.1063/1.1658107

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

New measurements of the CdS absorption edge on samples of different thickness provide strong evidence that the absorption takes place primarily in the surface region. Quite good agreement is obtained with calculations based on the Franz‐Keldysh effect.

ISSN:0021-8979    

DOI:10.1063/1.1658108

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The dynamic compaction properties of 1.3‐, 2.2‐, 3.3‐, 4.7‐, 5.8‐, and 7.0‐g/cc porous iron as determined from air gun plate impact experiments are described. The data indicate that the final pressure‐particle velocity states produced by impacting the three lower density materials are well approximated by a simple locking‐type model, neglecting elastic response of the material. In contrast, the higher density materials exhibit definite yield points and well‐defined states of partial compaction below about 26 kbar. These states are described in terms of the measured yield points and the properties of solid iron. At pressures above the 26 kbar necessary for complete compaction, agreement was observed between the data and the predictions using Hugoniot theory with the Gruneisen equation of state.

ISSN:0021-8979    

DOI:10.1063/1.1658109

出版商:AIP    

年代:1969

数据来源: AIP