358 results about "Nickel silicide" patented technology

In one aspect, methods of silicidation and germanidation are provided. In some embodiments, methods for forming metal silicide can include forming a non-oxide interface, such as germanium or solid antimony, over exposed silicon regions of a substrate. Metal oxide is formed over the interface layer. Annealing and reducing causes metal from the metal oxide to react with the underlying silicon and form metal silicide. Additionally, metal germanide can be formed by reduction of metal oxide over germanium, whether or not any underlying silicon is also silicided. In other embodiments, nickel is deposited directly and an interface layer is not used. In another aspect, methods of depositing nickel thin films by vapor phase deposition processes are provided. In some embodiments, nickel thin films are deposited by ALD. Nickel thin films can be used directly in silicidation and germanidation processes.

When a natural oxide film is left at the interface between a metal silicide layer and a silicon nitride film, in various heating steps (steps involving heating of a semiconductor substrate, such as various insulation film and conductive film deposition steps) after deposition of the silicon nitride film, the metal silicide layer partially abnormally grows due to oxygen of the natural oxide film occurring on the metal silicide layer surface. A substantially non-bias (including low bias) plasma treatment is performed in a gas atmosphere containing an inert gas as a main component on the top surface of a metal silicide film of nickel silicide or the like over source/drain of a field-effect transistor forming an integrated circuit. Then, a silicon nitride film serving as an etching stop film of a contact process is deposited. As a result, without causing undesirable cutting of the metal silicide film, the natural oxide film over the top surface of the metal silicide film can be removed.

Embodiments are provided for a method to deposit barrier and tungsten materials on a substrate. In one embodiment, a method provides forming a barrier layer on a substrate and exposing the substrate to a silane gas to form a thin silicon-containing layer on the barrier layer during a soak process. The method further provides depositing a tungsten nucleation layer over the barrier layer and the thin silicon-containing layer during an atomic layer deposition process and depositing a tungsten bulk layer on the tungsten nucleation layer during a chemical vapor deposition process. In some examples, the barrier layer contains metallic cobalt and cobalt silicide, or metallic nickel and nickel silicide. In other examples, the barrier layer contains metallic titanium and titanium nitride, or metallic tantalum and tantalum nitride.

A nonvolatile semiconductor memory device of a split gate structure having a gate of low resistance suitable to the arrangement of a memory cell array is provided. When being formed of a side wall spacer, a memory gate is formed of polycrystal silicon and then replaced with nickel silicide. Thus, its resistance can be lowered with no effect on the silicidation to the selection gate or the diffusion layer.

The introduction of a barrier diffusion material, such as nitrogen, into a silicon-containing conductive region, for example the drain and source regions and the gate electrode of a field effect transistor, allows the formation of nickel silicide, which is substantially thermally stable up to temperatures of 500° C. Thus, the device performance may significantly improve as the sheet resistance of nickel silicide is significantly less than that of nickel disilicide.

A semiconductor device fabrication method by which the thermal stability of nickel silicide can be improved. Nickel (or a nickel alloy) is formed over a semiconductor substrate on which a gate region, a source region, and a drain region are formed. Dinickel silicide is formed by performing a first annealing step, followed by a selective etching step. By performing a plasma treatment step, plasma which contains hydrogen ions is generated and the hydrogen ions are implanted in the dinickel silicide or the gate region, the source region, and the drain region under the dinickel silicide. The dinickel silicide is phase-transformed into nickel silicide by performing a second annealing step.

The present invention is to possible to avoid an inconvenience at a coupling portion between a barrier metal film obtained by depositing a titanium nitride film on a titanium film and thus having a film stack structure and a metal film filled, via the barrier metal film, in a connecting hole opened in an insulating film. The manufacturing method of a semiconductor device includes the steps of: forming a contact hole and exposing a nickel silicide layer from the bottom of the contact hole; forming a thermal reaction Ti film by a thermal reaction using a TiCl₄ gas, forming a plasma reaction Ti film by a plasma reaction using a TiCl₄ gas, carrying out plasma treatment with an H₂ gas to decrease the chlorine concentration of the plasma reaction Ti film and at the same time to reduce an oxide film on the surface of the nickel silicide layer; forming a nitrogen-rich TiN film over the surface of the plasma reaction Ti film and at the same time reducing the oxide film on the surface of the nickel silicide layer by thermal nitridation treatment with an NH₃ gas and plasma treatment with an NH₃ gas.

A nickel salicide process includes preparing a substrate having a silicon region and an insulating region containing silicon. Nickel is deposited on the substrate, and the nickel is annealed at a first temperature of 300° C. to 380° C. to selectively form a mono-nickel mono-silicide layer on the silicon region and to leave an unreacted nickel layer on the insulating region. The unreacted nickel layer is selectively removed to expose the insulating region and to leave the mono-nickel mono-silicide layer on the silicon region. Subsequently, the mono-nickel mono-silicide layer is annealed at a second temperature which is higher than the first temperature to form a thermally stable mono-nickel mono-silicide layer and without a phase transition of the mono-nickel mono-silicide layer.

A semiconductor structure in which the contact resistance in the contact opening is reduced as well as a method of forming the same are provided. This is achieved in the present invention by replacing conventional contact metallurgy, such as tungsten, or a metal silicide, such as Ni silicide or Cu silicide, with a metal germanide-containing contact material. The term “metal germanide-containing” is used in the present application to denote a pure metal germanide (i.e., MGe alloy) or a metal germanide that includes Si (i.e., MSiGe alloy).

The present invention relates to a method for forming self-aligned metal silicide contacts over at least two silicon-containing semiconductor regions that are spaced apart from each other by an exposed dielectric region. Preferably, each of the self-aligned metal silicide contacts so formed comprises at least nickel silicide and platinum silicide with a substantially smooth surface, and the exposed dielectric region is essentially free of metal and metal silicide. More preferably, the method comprises the steps of nickel or nickel alloy deposition, low-temperature annealing, nickel etching, high-temperature annealing, and aqua regia etching.

Provided is a technology of carrying out activation annealing of n type impurity ions implanted for the formation of a field stop layer (n⁺ type semiconductor region) and activation annealing of p type impurity ions implanted for the formation of a collector region (p⁺ type semiconductor region) in separate steps to adjust an activation ratio of the n type impurity ions in the field stop layer to 60% or greater and an activation ratio of the p type impurity ions in the collector region to from 1 to 15%. This makes it possible to form an IGBT having a high breakdown voltage and high-speed switching characteristics. Moreover, use of a film stack made of nickel silicide, titanium, nickel and gold films for a collector electrode makes it possible to provide an ohmic contact with the collector region.

A method of manufacturing a semiconductor device according to the present invention includes the steps of introducing first impurities of a first conductivity type into a main surface of a semiconductor substrate 1 to form a first impurity region, introducing second impurities of a second conductivity type to form a second impurity region, forming a first nickel silicide film on the first impurity region and forming a second nickel silicide film on the second impurity region, removing an oxide film formed on each of the first and second nickel silicide films by using a mixed gas having an NH₃ gas and a gas containing a hydrogen element mixed therein, and forming a first conducting film on the first nickel silicide film and forming a second conducting film on the second nickel silicide film, with the oxide film removed.

Gap filling between features which are closely spaced is significantly improved by initially depositing a thin conformal layer followed by depositing a layer of gap filling dielectric material. Embodiments include depositing a thin conformal layer of silicon nitride or silicon oxide, as by atomic layer deposition or pulsed layer deposition, into the gap between adjacent gate electrode structures such that it flows into undercut regions of dielectric spacers on side surfaces of the gate electrode structures, and then depositing a layer of BPSG or P-HDP oxide on the thin conformal layer into the gap. Embodiments further include depositing the layers at a temperature less than 430° C., as by depositing a P-HDP oxide after depositing the conformal liner when the gate electrode structures include a layer of nickel silicide.

The invention relates the reclaiming nickel-to-cobalt method from nickel oxide ore and silicic acid nickel ore, comprising the following steps: milling the nickel oxide ore and silicic acid nickel ore to -200 mesh, adding 5-15% coke breeze, 10-30% chloration agent, and 0.1-1.0% adjuvant to make 5-15mm pellet, adopting chloridising separating and roasting, controlling the high temperature of rotary kiln at 1000-1300Deg.C and back kiln at 400-600Deg.C, the rotation rate of rotary kiln being 0.75-2 revolution per minute, time being 1-2 hours, then putting the product into magnet separator whose magnetic density is 1500-3000G, finally getting the cobalt-nickel ore, whose nickel grade is 5-15%, and recovery ratio is 80-85%, and whose cobalt grade is 0.3-1.7%, and recovery ratio is 70-80%.

Nickel silicide is formed on the basis of a gaseous precursor, such as nickel tetra carbonyl, wherein the equilibrium of the decomposition of this gas may be controlled to obtain a highly selective nickel silicide formation rate. Moreover, any etch step for removing excess nickel may be avoided, since only minute amounts of nickel may form on exposed surfaces, which may then be effectively removed by correspondingly shifting the equilibrium. Consequently, reduced process complexity, enhanced controllability and enhanced tool lifetime may be obtained.

By maintaining the gate electrode covered during the process flow for forming metal silicide regions in the drain and source of a field effect transistor, an appropriate metal silicide may be formed on the gate electrode which meets the requirement for aggressive gate length scaling. Preferably, a nickel silicide is formed on the gate electrode, whereas the drain and source regions receive the well-established cobalt disilicide. Additionally, the gate electrode dopant profile is effectively decoupled from the drain and source dopant profile.

To provide a technique capable of improving the reliability of a semiconductor element and its product yield by reducing the variations in the electrical characteristic of a metal silicide layer. After forming a nickel-platinum alloy film over a semiconductor substrate 1, by carrying out a first thermal treatment at a thermal treatment temperature of 210 to 310° C. using a heater heating device, the technique causes the nickel-platinum alloy film and silicon to react with each other to form a platinum-added nickel silicide layer in a (PtNi)₂Si phase. Subsequently, after removing the unreacted nickel-platinum alloy film, the technique carries out a second thermal treatment having the thermal treatment temperature higher than that of the first thermal treatment to form the platinum-added nickel silicide layer in a PtNiSi phase. The temperature rise rate of the first thermal treatment is set to 10° C./s or more (for example, 30 to 250° C./s) and the temperature rise rate of the second thermal treatment is set to 10° C./s or more (for example, 10 to 250° C./s).

By forming a buried nickel silicide layer followed by a cobalt silicide layer in silicon-containing regions, such as a gate electrode of a field effect transistor, the superior characteristics of both silicides may be combined so as to provide the potential for further device scaling without unduly compromising the sheet resistance and the contact resistance of scaled silicon circuit features.

A technology is provided which allows, in a coupling portion obtained by burying a conductive material within a coupling hole bored in an insulating film, the removal of a natural oxide film on the surface of a silicide layer which is present at the bottom portion of the coupling hole. A coupling hole is bored in an interlayer insulating film (first and second insulating films) to expose the surface of a nickel silicide layer at the bottom portion of the coupling hole. Then, reduction gases including a HF gas and a NH₃ gas is supplied to the principal surface of a semiconductor wafer to form a product by a reduction reaction, and remove the natural oxide film on the surface of the nickel silicide layer. At this time, the flow rate ratio (HF/NH₃ gas flow rate ratio) between the NF gas and the NH₃ gas is adjusted to be more than 1 and not more than 5. Preferably, the temperature of the semiconductor wafer is adjusted to be not more than 30° C. Thereafter, a heating process is performed at 400° C. to the semiconductor wafer to remove the product remaining on the principal surface of the semiconductor wafer, and subsequently form a barrier metal film.