The preparation of Ru and RuO2 thin films by organometallic chemical vapor deposition and an investigation of the films' properties are reported. Ru is of interest for metallization in integrated circuit fabrication because its thermodynamically stable oxide, RuO2 , also exhibits metallic conductivity. As a result, oxidation during processing of Ru is a less critical concern than in current metallization technology. Taking advantage of the benefits of chemical vapor deposition, such as conformal coverage and low temperature, damage‐free deposition, we have deposited Ru, RuO2 , and normalRu/RuO2 by pyrolysis of three organoruthenium complexes. Films of a given phase composition were deposited under a wide variety of conditions and exhibited large variations in electrical resistivity and carbon content. The best Ru film, produced from Ru3false(CO)12 at 300°C in vacuum, had a resistivity of 16.9 μΩ‐cm and exhibited excellent adhesion to Si and SiO2 substrates. The best RuO2 film, produced from normalRufalse(C5H5)2 at 575°C in O2 , had a resistivity of 89.9 μΩ‐cm and similarly exhibited excellent adhesion. Rutherford backscattering studies show that Ru and RuO2 films are effective diffusion barriers between Al and Si up to annealing temperatures of about 550° and 600°C false(1/2 normalh exposurefalse) , respectively. Thus, they are significantly better than the currently used W films, which are only effective to about 500°C.

We have grown linearly compositionally graded GexSi1−x structures at high temperatures (700–900°C) on Si substrates to form a surface which resembles a GexSi1−x substrate. We have obtained completely relaxed structures with x≤0.50 and threading dislocation densities in the 105cm−2 - 106cm−2 range. Because of the very low threading dislocation densities, the structures appear dislocation free in conventional transmission electron microscopy (TEM) cross-section and plan view. Employing the electron beam induced current technique (EBIC), we were able to consistently measure these low threading dislocation densities. A direct comparison of two x=0.35 films, one graded in Ge content and one uniform in Ge content, shows that compositional grading decreases the dislocation density by a factor of 100–1000. These. higher quality graded buffers have been used as templates for the subsequent growth of InGaP light emitting diodes (LED) and GexSi1−x/Si two-dimensional electron gas (2DEG) structures. Room temperature operation of orange-red LEDs were obtained at current densities of =600A/cm, and mobilities as high as 96,000 cm2/V-s were achieved at 4.2K in the 2DEG structures.

This study assesses the use of selective LPCVD tungsten as a contact barrier in VLSI circuits. Measurements of the contact resistance and leakage current are evaluated as a function of variations in W deposition parameters, implant type, implant dosage, and metallization heat‐treatment. Addition of SiF4 to alter the equilibrium of the displacement reaction is seen to cause minimal erosion and encroachment of the Si contacts as well as produce low and thermally stable contact resistances to both n+ and p+ diffusions. For surface doping concentrations of 1.44×1020 cm−3 normalAs and 0.62×1020 cm−3B , measured values of the contact resistance for 2.0 μm sized vias are near 30Ω. Such values are quite compatible with high performance CMOS device requirements. Further reductions in these values are achieved with use of a self‐aligned normalPtSi/W contact barrier metallization. The contact resistance for 2.0 μm sized vias are, in this case, near 4 and 15OHgr; for the n+ and p+diffusions, respectively. Sporadic leakage across shallow n+/P‐Tub junctions remains, however, a serious problem associated with this selective LPCVD W process. Understanding the origin of this leakage and eliminating it can lead to numerous applications of this technology in VLSI manufacturing.

The absolute nitrogen concentration in SiOxNy/Si films grown by rapid thermal oxidation in N2O has been determined by nuclear reaction analysis. Compared with conventional surface analysis methods, i.e., Auger electron spectroscopy, x-ray photoelectron spectroscopy, and secondary ion mass spectrometry, the nuclear reaction 14N(d,α)12C provides more accurate depth profiles of 14N due to the quantitative nature of the technique and its high sensitivity, ∼6.0×1013 atoms cm2. Silicon oxynitride films prepared under various conditions, specifically different growing temperatures and times, were analyzed. Nitrogen is observed to accumulate in a narrow region in the oxynitride (within ≲2.5 nm) close to the interface; the total amount of nitrogen increases with increasing temperature and growth time.

This paper reviews the current status of LPCVD tungsten and aluminum for VLSI applications. Using deposition chemistries based on tungsten hexafluoride and tri-isobutyl aluminum, W and A1 deposits are characterized with respect to their electrical, mechanical, structural, chemical, and optical properties. Although results of this study prove these two LPCVD processes to be compatible with current VLSI fabrication, certain problems must still be resolved for complete commercial acceptance. These problems include, in the case of selective LPCVD tungsten, the occurrence of leakage current across N+/P-Tub junctions, and, in the case of LPCVD aluminum, the relatively poor electromigration resistance (compared to A1-Cu) and excess surface roughness.Low pressure chemical vapor deposition (LPCVD) is a widely used technology for producing thin films in the semiconductor industry (1). Its advantages are manifested in the quality of the films produced and in the economy of the process. Film characteristics such as conformal coverage and high purity are coupled to processing benefits such as low temperature deposition, absence of radiation damage, selectivity, throughput, and proper control over film stress and grain size to insure the reliable fabrication of unique microelectronic structures.Although LPCVD of polycrystalline silicon and insulators (e.g., oxides and nitrides) is firmly entrenched in the