The rate of rod fallover in the production of polycrystalline silicon by the Siemens process is sharply reduced by cleaning the Siemens reactor base plate by at least a two-step procedure comprising suctioning the base plate in one step, and subsequently cleaning with liquid or solid cleaning medium in a second step, between each phase of rod removal and new support body installation.

The rate of rod fallover in the production of polycrystalline silicon by the Siemens process is sharply reduced by cleaning the Siemens reactor base plate by at least a two-step procedure comprising suctioning the base plate in one step, and subsequently cleaning with liquid or solid cleaning medium in a second step, between each phase of rod removal and new support body installation.

A method for transferring a graphene sheet from a copper substrate to a functional substrate includes forming the graphene sheet on the copper substrate using chemical vapor deposition, and irradiating the graphene sheet disposed on the copper substrate with a plurality of xenon ions using broad beam irradiation to form a prepared graphene sheet. The prepared graphene sheet is resistant to forming unintentional defects induced during transfer of the prepared graphene sheet to the functional substrate. The method further includes removing the copper substrate from the prepared graphene sheet using an etchant bath, floating the prepared graphene sheet in a floating bath, submerging the functional substrate in the floating bath, and decreasing a fluid level of the floating bath to lower the prepared graphene sheet onto the functional substrate.

A method of forming a membrane is described. A graphenic-based membrane is formed on a growth substrate, where the graphenic-based membrane have one or more layers of graphenic-based material. The graphenic-based membrane is removed from the growth substrate. A region of the graphenic-based membrane having intrinsic or native defects is identified. The region of the graphenic-based membrane is irradiated with charged particles while introducing carbonaceous material on a surface of the one or more layers of graphenic-based material to heal the intrinsic or native defects.

A graphene sheet including an intercalation compound and 2 to about 300 unit graphene layers, wherein each of the unit graphene layers includes a polycyclic aromatic molecule in which a plurality of carbon atoms in the polycyclic aromatic molecule are covalently bonded to each other; and wherein the intercalation compound is interposed between the unit graphene layers.

A graphene sheet including an intercalation compound and 2 to about 300 unit graphene layers, wherein each of the unit graphene layers includes a polycyclic aromatic molecule in which a plurality of carbon atoms in the polycyclic aromatic molecule are covalently bonded to each other; and wherein the intercalation compound is interposed between the unit graphene layers.

A process for making low resistivity CVC silicon carbide. Applicants have developed a better process for adding nitrogen to silicon carbide which has the safety economic advantages of doping with N.sub.2 with the ease of N.sub.2 release advantages of using NH.sub.3. Preferred embodiments of the present invention include a NH.sub.3 generator with a source of H.sub.2 and a source of N.sub.2 and an arc discharge apparatus adapted to produce NH.sub.3 gas from a combination of the H.sub.2 and N.sub.2 sources.

A process for making low resistivity CVC silicon carbide. Applicants have developed a better process for adding nitrogen to silicon carbide which has the safety economic advantages of doping with N.sub.2 with the ease of N.sub.2 release advantages of using NH.sub.3. Preferred embodiments of the present invention include a NH.sub.3 generator with a source of H.sub.2 and a source of N.sub.2 and an arc discharge apparatus adapted to produce NH.sub.3 gas from a combination of the H.sub.2 and N.sub.2 sources.

Embodiments of the present disclosure relate to processes for filling trenches. The process includes depositing a first amorphous silicon layer on a surface of a layer and a second amorphous silicon layer in a portion of a trench formed in the layer, and portions of side walls of the trench are exposed. The first amorphous silicon layer is removed. The process further includes depositing a third amorphous silicon layer on the surface of the layer and a fourth amorphous silicon layer on the second amorphous silicon layer. The third amorphous silicon layer is removed. The deposition/removal cyclic processes may be repeated until the trench is filled with amorphous silicon layers. The amorphous silicon layers form a seamless amorphous silicon gap fill in the trench since the amorphous silicon layers are formed from bottom up.

Embodiments of the present disclosure relate to processes for filling trenches. The process includes depositing a first amorphous silicon layer on a surface of a layer and a second amorphous silicon layer in a portion of a trench formed in the layer, and portions of side walls of the trench are exposed. The first amorphous silicon layer is removed. The process further includes depositing a third amorphous silicon layer on the surface of the layer and a fourth amorphous silicon layer on the second amorphous silicon layer. The third amorphous silicon layer is removed. The deposition/removal cyclic processes may be repeated until the trench is filled with amorphous silicon layers. The amorphous silicon layers form a seamless amorphous silicon gap fill in the trench since the amorphous silicon layers are formed from bottom up.