摘要:
A graphene layer is formed on a crystallographic surface having a non-hexagonal symmetry. The crystallographic surface can be a surface of a single crystalline semiconductor carbide layer. The non-hexagonal symmetry surface of the single crystalline semiconductor carbide layer is annealed at an elevated temperature in ultra-high vacuum environment to form the graphene layer. During the anneal, the semiconductor atoms on the non-hexagonal surface of the single crystalline semiconductor carbide layer are evaporated selective to the carbon atoms. As the semiconductor atoms are selectively removed, the carbon concentration on the surface of the semiconductor-carbon alloy layer increases. Despite the non-hexagonal symmetry of the surface of the semiconductor-carbon alloy layer, the remaining carbon atoms can coalesce to form a graphene layer having hexagonal symmetry.
摘要:
A graphene layer is formed on a crystallographic surface having a non-hexagonal symmetry. The crystallographic surface can be a surface of a single crystalline semiconductor carbide layer. The non-hexagonal symmetry surface of the single crystalline semiconductor carbide layer is annealed at an elevated temperature in ultra-high vacuum environment to form the graphene layer. During the anneal, the semiconductor atoms on the non-hexagonal surface of the single crystalline semiconductor carbide layer are evaporated selective to the carbon atoms. As the semiconductor atoms are selectively removed, the carbon concentration on the surface of the semiconductor-carbon alloy layer increases. Despite the non-hexagonal symmetry of the surface of the semiconductor-carbon alloy layer, the remaining carbon atoms can coalesce to form a graphene layer having hexagonal symmetry.
摘要:
A graphene layer is formed on a crystallographic surface having a non-hexagonal symmetry. The crystallographic surface can be a surface of a single crystalline semiconductor carbide layer. The non-hexagonal symmetry surface of the single crystalline semiconductor carbide layer is annealed at an elevated temperature in ultra-high vacuum environment to form the graphene layer. During the anneal, the semiconductor atoms on the non-hexagonal surface of the single crystalline semiconductor carbide layer are evaporated selective to the carbon atoms. As the semiconductor atoms are selectively removed, the carbon concentration on the surface of the semiconductor-carbon alloy layer increases. Despite the non-hexagonal symmetry of the surface of the semiconductor-carbon alloy layer, the remaining carbon atoms can coalesce to form a graphene layer having hexagonal symmetry.
摘要:
A single crystalline silicon carbide layer can be grown on a single crystalline sapphire substrate. Subsequently, a graphene layer can be formed by conversion of a surface layer of the single crystalline silicon layer during an anneal at an elevated temperature in an ultrahigh vacuum environment. Alternately, a graphene layer can be deposited on an exposed surface of the single crystalline silicon carbide layer. A graphene layer can also be formed directly on a surface of a sapphire substrate or directly on a surface of a silicon carbide substrate. Still alternately, a graphene layer can be formed on a silicon carbide layer on a semiconductor substrate. The commercial availability of sapphire substrates and semiconductor substrates with a diameter of six inches or more allows formation of a graphene layer on a commercially scalable substrate for low cost manufacturing of devices employing a graphene layer.
摘要:
A single crystalline silicon carbide layer can be grown on a single crystalline sapphire substrate. Subsequently, a graphene layer can be formed by conversion of a surface layer of the single crystalline silicon layer during an anneal at an elevated temperature in an ultrahigh vacuum environment. Alternately, a graphene layer can be deposited on an exposed surface of the single crystalline silicon carbide layer. A graphene layer can also be formed directly on a surface of a sapphire substrate or directly on a surface of a silicon carbide substrate. Still alternately, a graphene layer can be formed on a silicon carbide layer on a semiconductor substrate. The commercial availability of sapphire substrates and semiconductor substrates with a diameter of six inches or more allows formation of a graphene layer on a commercially scalable substrate for low cost manufacturing of devices employing a graphene layer.
摘要:
remove impurities from an exposed surface in the ultrahigh vacuum environment. A high qualify single crystalline or polycrystalline silicon carbide film can be grown directly on the sapphire substrate by chemical vapor deposition employing a silicon-containing reactant and a carbon-containing reactant. Formation of single crystalline silicon carbide has been verified by x-ray diffraction, secondary ion mass spectroscopy, and transmission electron microscopy.
摘要:
A surface of a single crystalline semiconductor-carbon alloy layer having a surface normal along or close to a major crystallographic direction is provided by mechanical means such as cutting and/or polishing. Such a surface has naturally formed irregular surface features. Small semiconductor islands are deposited on the surface of single crystalline semiconductor-carbon alloy layer. Another single crystalline semiconductor-carbon alloy structure may be placed on the small semiconductor islands, and the assembly of the two semiconductor-carbon alloy layers with the semiconductor islands therebetween is annealed. During the initial phase of the anneal, surface diffusion of the semiconductor material proceeds to form vicinal surfaces while graphitization is suppressed because the space between the two semiconductor-carbon alloy layers maintains a high vapor pressure of the semiconductor material. Once all semiconductor material is consumed, graphitization occurs in which graphene layers can be formed on the vicinal surfaces having atomic level surface flatness.
摘要:
A surface of a single crystalline semiconductor-carbon alloy layer having a surface normal along or close to a major crystallographic direction is provided by mechanical means such as cutting and/or polishing. Such a surface has naturally formed irregular surface features. Small semiconductor islands are deposited on the surface of single crystalline semiconductor-carbon alloy layer. Another single crystalline semiconductor-carbon alloy structure may be placed on the small semiconductor islands, and the assembly of the two semiconductor-carbon alloy layers with the semiconductor islands therebetween is annealed. During the initial phase of the anneal, surface diffusion of the semiconductor material proceeds to form vicinal surfaces while graphitization is suppressed because the space between the two semiconductor-carbon alloy layers maintains a high vapor pressure of the semiconductor material. Once all semiconductor material is consumed, graphitization occurs in which graphene layers can be formed on the vicinal surfaces having atomic level surface flatness.
摘要:
This invention provides structures and a fabrication process for incorporating thin film transistors in back end of the line (BEOL) interconnect structures. The structures and fabrication processes described are compatible with processing requirements for the BEOL interconnect structures. The structures and fabrication processes utilize existing processing steps and materials already incorporated in interconnect wiring levels in order to reduce added cost associated with incorporating thin film transistors in the these levels. The structures enable vertical (3D) integration of multiple levels with improved manufacturability and reliability as compared to prior art methods of 3D integration.
摘要:
This invention provides structures and a fabrication process for incorporating thin film transistors in back end of the line (BEOL) interconnect structures. The structures and fabrication processes described are compatible with processing requirements for the BEOL interconnect structures. The structures and fabrication processes utilize existing processing steps and materials already incorporated in interconnect wiring levels in order to reduce added cost associated with incorporating thin film transistors in the these levels. The structures enable vertical (3D) integration of multiple levels with improved manufacturability and reliability as compared to prior art methods of 3D integration.