摘要:

The deposition of Co thin films by organometallic chemical vapor deposition is reported. Co is of interest in very large scale integration technology as a catalyst for electroless plating of other metals and as a precursor to formation of CoSi2. High purity, conformal films of Co are deposited by pyrolysis of Co2(CO)8at 200 °C in vacuum. These films exhibit electrical resistivities of 5–10 μΩ cm and excellent adhesion to Si and SiO2. CoSi2is formed by heating the samples at 700 °C. The CoSi2films resulting from reaction of the Co films with the Si substrate contain larger grains than the starting film and exhibit electrical resistivities of ∼13–37 μΩ cm. Selective formation of CoSi2on patterned test wafers shows similar attributes.

ISSN:1071-1023    

DOI:10.1116/1.584212

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

The compounds [Co(CO)3XEt3]2,X=P,As, have been evaluated as possible precursors for the deposition of the cobalt pnictides, CoX. Thermogravimetric analysis and x‐ray diffraction reveal loss of the 1:1 Co:X stoichiometry of the starting material upon thermal decomposition. The decomposition products consist of mixed Co and Co2X phases.

ISSN:1071-1023    

DOI:10.1116/1.584213

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

The kinetics of low‐energy electron beam induced metal film nucleation have been investigated. Experiments performed were the deposition of Fe and Cr from Fe(CO)5and Cr(CO)6, respectively. It was found that the activation energy for the autocatalytic thermal decomposition of these compounds was lower than the activation energy for decomposition on Si surface. The autocatalytic activation energies were measured as 0.14 eV for Fe(CO)5and 1.02 eV for Cr(CO)6. The electron beam induced nucleation, together with the rapid autocatalytic decomposition, allowed for selective area metal film growth. A qualitative model based on classical nucleation theory describes well the effect of electron irradiation in inducing film growth. The electron beam induced nucleation step has been modeled in more detail and shows at4dependence for the early stages of film growth, in agreement with the observed data.

ISSN:1071-1023    

DOI:10.1116/1.584214

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

A fast atom beam technique is applied to silicon dioxide substrate pattern fabrication. A modified Mcllraith (saddle field) fast atom source having a charge exchange cell in front of the cathode grid is studied under several discharge conditions. High pressure in the source is shown to increase the proportion of high‐energy neutral particles in the beam. The tendencies of the neutralizations are in accordance with calculations based on resonance charge transfer. Maximum etch rates for Si and SiO2using a CF4+O2gas mixture are achieved at a relative CF4gas flow rate of 0.76, and the etch rate for SiO2, unlike that for Si, is found to depend linearly on the discharge current. The etched sidewalls at a discharge voltage of 1.2 kV were nearly perpendicular. Reactive fast atom beam etching proved capable of producing highly accurate 0.2‐μm‐wide pattern formations.

ISSN:1071-1023    

DOI:10.1116/1.584215

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

Ions and neutrals sampled from a NF3/O2etching plasma were observed by a quadrupole mass spectrometer and cylindrical mirror ion energy analyzer to investigate ion‐bombardment‐enhanced etching of tungsten. Dc biasing of a 13.56 MHz, 2.7 Pa, 1.24 W/cm2, 3/1 NF3/O2glow discharge raised the average ion energy bombarding the grounded electrode from 35 to 172 eV concurrent with an increase in the ion current by a factor of 3. Total conversion of NF3to N2and F2occurred under these conditions yielding a typical etch rate of polycrystalline tungsten of 150 nm/min. The primary ion observed was WF+5. The WF6etch product concentration was independent of ion energy, but correlated strongly with ion current. The results support a damage‐induced chemical reaction as the enhancement mechanism.

ISSN:1071-1023    

DOI:10.1116/1.584216

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

The reactive ion etching damage occurring in GaAs/AlGaAs heterostructure devices etched in CCl2F2and He at low‐self‐bias voltages (−85 V) was characterized by Schottky diodes. The effect of overetching was examined by etching down to a thin AlAs etch stop layer and electrically characterizing the underlying GaAs layers. Simultaneously etched bulk samples displayed less damage, indicating that bulk samples may not give a true indication of the damage in heterojunction samples. It was deduced that helium ions are most probably responsible for the damage observed.

ISSN:1071-1023    

DOI:10.1116/1.584217

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

Thin films of molybdenum were etched both within and downstream from a Cl2plasma at 200‐mTorr pressure and temperatures below 180 °C. When samples were positioned downstream from the discharge, etching proceeded solely by chemical reaction of the film with chlorine atoms. Without a discharge, molecular chlorine did not etch molybdenum. Downstream and in‐discharge etch rates were<20 nm/min and etching by atoms was not observed below 100 °C. The chemical reaction between chlorine atoms and molybdenum was proportional to the gas phase Cl atom mole fraction.

ISSN:1071-1023    

DOI:10.1116/1.584218

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

Silicon etching rates up to 250 Å/min have been observed in an electron‐beam‐generated He plus SF6plasma. The etch rate was found to increase linearly with electron beam current density and to be practically independent of the electron acceleration voltage in the range investigated (170–260 V). Profiles of the resulting features show that etching is anisotropic with a vertical‐to‐horizontal ratio of 2.5 to 3.

ISSN:1071-1023    

DOI:10.1116/1.584219

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

GaAs etching process has been studied in Ar–Cl2rf discharges at 200 mTorr as a function of gas composition, substrate temperature, and bias voltage. Actinometric optical emission spectroscopy has been utilized for gas phase diagnostic. Surface analysis has been carried out by x‐ray photoelectron spectroscopy and scanning electron microscopy. Anomalies found in the etching regimes have been interpreted as caused by the presence of an inhibiting oxide–chloride film and by the desorption of chlorine adsorbed on the surface by low‐energy bombarding ions.

ISSN:1071-1023    

DOI:10.1116/1.584187

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

A selective dry process is used to fabricate epitaxial diaphragms by etching anisotropic cavities through a GaAs substrate to an AlGaAs stop‐etch layer. Active devices are built directly on the layers comprising the diaphragm. The etching process follows the device fabrication sequence, facilitating integration of these structures with pre‐existing electronic circuitry. Potential applications in optoelectronic and acoustic wave devices are discussed, and an optical interconnection technique based on the diaphragm structure is described.

ISSN:1071-1023    

DOI:10.1116/1.584176

出版商:American Vacuum Society    

年代:1988

数据来源: AIP