High-alloy metals reinforced by diamond-like framework and method for making the same

Abstract

A new class of high-alloy metals is invented. The metals possess an amorphous, nano crystalline, or combined amorphous-nano-crystalline structure and are reinforced, stabilized and hardened with a framework formed by predominantly sp3-bonded carbon, also known-as diamond like carbon. Optionally, other alloying nonmetallic elements selected from the group of Si, B, O, N may additionally stabilize the structure. The disclosed high-alloy metals comprise a metallic matrix which may include iron, nickel, chromium, refractory, and various other metals. These materials are very stable, and do not suffer a structural degradation up to relatively high temperatures. The disclosed high-alloy metals have the properties of high hardness, corrosion and wear resistance, and low friction. They have a wide range of applications as protective coatings on a wide variety of materials in various industries. They may be further applied as magnetic and electronic devices, such as field emission cathodes. Some of these alloys possess high emissivity, and their electrical conductivity may be varied in a relatively wide range.

Description

RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Patent Application No. 60 / 506,336, entitled “HIGH-ALLOY METALS REINFORCED BY DIAMOND-LIKE FRAMEWORK AND METHOD OF MAKING THE SAME”, filed on Sep. 25, 2003BACKGROUND OF THE INVENTION [0002] The present invention relates to metal alloys. Particularly the invention relates to amorphous metals or metal-metalloids alloyed with non-metallic elements. [0003] Over the past few decades, amorphous alloys have been produced with various characteristics with regard to magnetic, mechanical, and chemical properties, electrical resistivity, and corrosion resistance, and also at a relatively low cost. For instance, various amorphous Fe group alloys, Pd-alloys, Cu alloys, Zr alloys, and Ti-alloys have been produced by rapidly cooling the molten alloy. These amorphous metals possess certain mechanical and chemical characteristics not achievable in crystalline materials. Rapid cooling technology, however, does not allow...

AI Technical Summary

Benefits of technology

[0020] This new class of amorphous and nano-crystalline alloys overcomes many barriers of existing technologies, by, in certain instances, simultaneously increasing the thermal stability and corrosion resistance of the high alloy amorphous metals and preserving many mechanical and tribological properties of diamond-like matter. The new amorphous or nano-crystalline high-alloy metals, intermetallics, and transition metal-metalloids possess very high uniformity and superior structural stability. They may be deposited upon various substrates as uniform, multi-layer or functionally graded coatings with a pre-designed multi-layer profile in one continuous deposition process. The deposited layers generally have excellent adhesion to the various substrates, and the interfaces between the layers of different compositions are self-consistent, the layers possess the proper amorphous or required nano-crystalline structure, and they do not require post-deposition amorphizing. In one embodiment, the deposition temperature is low, and the built-in stress is absent or extremely low. In one embodiment, the deposited layers are free from pores exceeding the diameter of metallic atoms, and the specific gravity of deposited materials is essentially below that of the corresponding crystalline alloys. The resistivity of said alloys is controllably variable up to higher values than available in pure metals or refractory intermetallics. The emissivity of certain of metal-metalloid-based alloys exceeds 0.8.

Problems solved by technology

Rapid cooling technology, however, does not allow for adequate control of the fine structure of solidifying metals.

Conventional ceramic materials, however, have low fracture toughness, especially at high temperatures, low strength, and poor reliability.

In order to obtain the lower resistivity C54 phase, a second high-temperature temperature annealing step is required that can have detrimental effects on the silicide and other integrated circuit elements, such as peeling and cracking of dielectric elements and a change of electrical characteristics of conducting elements.

On the other hand, if the phase transformation is not completed or is not uniform, very large scale integrated circuits experience accelerated degradation of structure and performance.

In some very large scale integrated circuits these types of failures may reach 5-10 percent.

Although various approaches were suggested to resolve this polymorphism problem, all of them suffer from similar deficiencies.

In addition, the crystalline structure of silicide causes a principle problem in forming a transistor gate with length of less than 0.1 microns.

Such a complex technology is necessary because no one silicide alone can satisfy simultaneously the requirements of adhesion, electrical resistivity, and self-aligned formation of the contacts.

On the other hand, the multi layer structure and CVD deposition result in problems with inter-layer and layer CVD gas media interaction.

However, such a partial amorphizing also introduces extra thermal steps in the VLIC technology, as well as additional substances, which may diffuse into the transistor structure and deteriorate its characteristics.

Furthermore, any post-amorphizing of an already formed solid does not create a uniform structure and usually results in built-in stress.

All these problems would become increasingly serious as the very large scale integrated circuit patterning advances into a sub-micron range.

However, this multi-step high-temperature process may be only applied for powder production.

However, to obtain finer structures, additional treatment steps are required.

The structural resolution of such post-solidification technology is still very limited, and only certain specific shapes of metal products like wire are feasible.

The thermal stability of produced structure is also not high enough for some applications.

Still some properties, such as ductility, thermal stability, and high-temperature oxidation resistance are not sufficient for many applications.

Additionally, the electrical conductivity of predominantly carbon materials is limited, while ferromagnetic properties and some other physical properties and metallic features are not achievable.

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