摘要:

The interfacial reaction of sputtered Ti films with borophosphosilicate glass (BPSG) sublayers has been studied using primarily Auger electron spectroscopy depth profiling techniques. Thin interfacial layers formed during rapid thermal annealing in N2ambients were studied as a function of temperature, time, BPSG composition, and sublayer preclean treatment. A P‐rich (phosphide) layer was found to accumulate at the Ti/BPSG interface during the reactions and in so doing inhibited the Ti/SiO2reduction reaction. B accumulated only when the consumption of the entire Ti film neared completion. In some cases, adhesion failures could be generated following the deposition of an Al metallization over the reacted Ti/BPSG films. These failures were found to occur between the P‐rich (phosphide) interfacial layer and the BPSG sublayer and could be prevented by backsputtering the BPSG prior to Ti depositon.

ISSN:1071-1023    

DOI:10.1116/1.586088

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

Plasma deposition of SiO2on silicon substrates in a microwave (2.45 GHz) electron cyclotron resonance N2O/SiH4/He discharge has been investigated as a function of radio frequency (13.56 MHz) self‐biasing of the sample, pressure, microwave power, substrate temperature, and gas mixture. Deposition rates between 30 and 90 nm/min have been observed with quality films over a range of parameter combinations. The films have been analyzed for thickness and index of refraction by ellipsometry and for chemical structure by Fourier transform infrared spectroscopy. The deposition process yielded films with virtually no Si–H, N–H, or Si–N bonding groups and only traces of OH bonds. Analysis of the Si–O–Si stretching peak reveals a film quality which compares favorably with good quality thermal oxides grown at much higher substrate bulk temperatures. Also, the relative insensitivity to the He content of the gas mixture indicates the surface chemistry of this process is fundamentally different from previously reported plasma enhanced chemical vapor deposition processes.

ISSN:1071-1023    

DOI:10.1116/1.586089

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

Silicon dioxide films have been deposited at low temperatures (200–250 °C) by microwave plasma enhanced decomposition of tetraethylorthosilicate (TEOS). The effects of the presence of oxygen in the discharge in film deposition rate, mechanism, and the physical properties of the films have been investigated. Structural characterization of the deposited films has been carried out by etch rate measurements, infrared transmission spectra, x‐ray photoelectron spectroscopy, Auger, and secondary ion mass spectrometry analyses. Films deposited using TEOS and oxygen have confirmed a density comparable to standard silane‐based low‐pressure chemical vapor deposition and plasma enhanced chemical vapor deposition oxides, nearly perfect stoichiometry, extremely low sodium and carbon content, and the absence of many undesirable hydrogen related bonds. Various electrical properties, viz., resistivity, breakdown strength, fixed oxide charge density, interface state density, and trapping behavior have been evaluated by the characterization of metal–oxide semiconductor capacitors fabricated using deposited oxides. Deposited films on thin native oxides grown by eitherinsituplasma oxidation or a low temperature thermal oxidation exhibited excellent electrical properties.

ISSN:1071-1023    

DOI:10.1116/1.586090

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

Up to 30 nm thick Ge layers were grown on Si(100) by using Sb as a surfactant and were investigated by reflection high‐energy electron diffraction, x‐ray photoelectron spectroscopy, secondary ion mass spectroscopy, transmission electron microscopy, and confocal laserscan microscopy. The introduction of a surfactant alters the growth mode drastically from a three‐dimensional clustering mechanism to a two‐dimensional layer‐by‐layer growth. Smooth and strained Ge layers, with a thickness much larger then the critical thickness for commensurate growth, are achievable. The antimony monolayer mainly segregates on top of the grown germanium layer.

ISSN:1071-1023    

DOI:10.1116/1.585879

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

The growth rate, resistivity, and selectivity of selective chemical vapor deposition of tungsten using SiH4reduction of WF6has been examined as a function of SiH4partial pressure (PP), WF6PP, growth temperature, total pressure, average residence time, and fraction of exposed area. The growth rate is proportional to the SiH4PP, decreases with increased temperature, and decreases with increased exposed area. The deposition rate also decreases slightly as the WF6to SiH4ratio increases. With a constant SiH4PP, the growth rate decreases as the total pressure increases (the SiH4flow rate is decreased at higher total pressures). The SiH4conversion efficiency increases as the residence time and fraction of exposed area increase. The resistivity decreases as the growth temperature increases or the deposition rate decreases. The resistance increases with increasing Si and F concentrations in the films. Low temperature residual resistance measurements indicated that the increase in resistance is due to impurity scattering. The selectivity is better at lower temperatures, low growth rates, high WF6to SiH4ratios, and intermediate pressures (25–100 mTorr). A mechanistic model of the deposition process is presented which explains much of the observed phenomenology.

ISSN:1071-1023    

DOI:10.1116/1.585880

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

We report on a two‐step process for the patterning and growth of aluminum films from the metallorganic source gas dimethylaluminum hydride (DMAlH). In particular, ultraviolet light from a cw or pulsed laser source is used to generate a seed layer for selective chemical vapor deposition of aluminum conductors. The dependence of growth selectivity on the temperature and substrate material, the influence of the seed‐layer thickness on film growth, and the process parameters such as temperature and pressure, that yield high purity aluminum, are presented. This technique has been applied to two applications with different materials requirements: final metallization of a complementary metal–oxide‐semiconductor gate array in silicon, and electrode formation for GaAs/AlGaAs integrated optical modulators.

ISSN:1071-1023    

DOI:10.1116/1.585881

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

The sheet conductance of Ni films deposited onto clean Si(111) substrates has been measured during deposition and after stepwise annealing. Hall effect, surface composition, and surface order have also been monitored. The dependence of compound formation on film thickness and temperature has been studied. It is shown that each silicide has a characteristic bulk conductivity and that the influence of surface scattering is small even for very thin films (≳1 nm).

ISSN:1071-1023    

DOI:10.1116/1.585882

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

The formation of titanium disilicide by the solid phase reaction of titanium with single crystal silicon has been studied using an electron beam heating method which gives well‐controlled, rapid time‐temperature cycles. Rapid heating of titanium coated silicon in the temperature range 750–1000 °C gives rise to titanium disilicide films having a low value of resistivity of about 15 μΩ cm. It is also reported that heating at relatively high temperatures does not preclude the formation of metastable titanium disilicide phases. Auger electron spectroscopy combined with Ar+ion sputter depth profiling of samples, which had been exposed to a number of different heat cycles, revealed that impurities such as oxygen and carbon, adsorbed in the titanium films, are driven towards the top surface. Cross‐sectional transmission electron microscopy analysis of a fully reacted sample showed that rapid heating resulted in a smooth interface between the silicide and the silicon substrate.

ISSN:1071-1023    

DOI:10.1116/1.585883

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

In this article a commerciale‐beam lithography machine (Leica Cambridge EBMF 10 cs/120) is used in metrological mode for critical dimension control of metal features with size down to 100 nm. The experimental backscattered electrons signal, collected by a channel plate detector, is described by an analytical function which is the convolution of probe beam function, detector transfer function, and specimen absorption transfer function. The further data processing by means of a developed software algorithm, allowed the determination of the significant structure parameters as linewidth and sidewall angle. Metal test structures, as isolated lines and grooves with size down to 100 nm, fabricated on silicon wafers, are successfully inspected and measured by this method. The comparison between computed dimensions and scanning electron microscopy measurements shows a good agreement (within 5%) for structures of different dimensions, varying their aspect ratio and the sidewall angle at their edges. The effect of beam diameter (BD) value on the measurement was also investigated and accurate measurements have been obtained for BD less than the structure dimension. Finally, a repeatability test performed on a sub‐200 nm gold feature showed a precision of 6 nm (3σSvalue) on a sample of one thousand measurements.

ISSN:1071-1023    

DOI:10.1116/1.585884

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

The application of pulse‐current gold plating has been studied in the fabrication of x‐ray mask patterns to attain uniform thickness and low stress. Pulse‐current plating with low average current density (iav) has proven effective in improving uniform plating thickness over a wide range of pattern sizes. This result can be explained through the duplex‐diffusion layer model. Stress in the gold plated by lowiavbecomes compressive. However, this stress can be eliminated by annealing. This annealing effect is attributable to the contraction in volume of plated gold due to the thermal desorption of hydrogen atoms.

ISSN:1071-1023    

DOI:10.1116/1.585885

出版商:American Vacuum Society    

年代:1992

数据来源: AIP