The process for manufacturing a silicon wafer includes steps for mounting a float zone silicon work piece for exfoliation, energizing a microwave device for generating an energized beam sufficient for penetrating an outer surface layer of the float zone silicon work piece, exfoliating the outer surface layer of the float zone silicon work piece with the energized beam, and removing the exfoliated outer surface layer from the float zone silicon work piece as the silicon wafer having a thickness less than 100 micrometers.

A method of performing regional heating of a substrate by electromagnetic induction heating. The method may include applying a semiconductor film to the substrate and controllably energizing a coil positioned near the substrate. The energized coil(s) thereby generates a magnetic flux, which induces a current in the substrate and/or the semiconductor film, thereby heating the substrate and/or semiconductor film. The method may also include relative motion between the coil and the substrate to provide translation heating of the semiconductor film. Additionally, a crystal seeding mechanism may be employed to further control the crystallization process.

A single crystal is pulled by an FZ method, in which a polycrystal is melted by means of an electromagnetic melting apparatus and then recrystallized, wherein a first phase (P.sub.1) a lower end of the polycrystal, which is moved toward the melting apparatus, is melted by the melting apparatus to form a drop, and in a second phase (P.sub.2) a monocrystal line seed is attached to the lower end of the polycrystal and is melted beginning from an upper end of the seed, where a power (P) of the melting apparatus during the first phase (P.sub.1) and during the second phase (P.sub.2) is predetermined at least temporarily in dependence on a temperature and/or geometrical dimensions of crystal material used which comprises the drop and/or the seed and/or the polycrystal.

A single crystal is pulled by an FZ method, in which a polycrystal is melted by means of an electromagnetic melting apparatus and then recrystallized, wherein a first phase (P.sub.1) a lower end of the polycrystal, which is moved toward the melting apparatus, is melted by the melting apparatus to form a drop, and in a second phase (P.sub.2) a monocrystal line seed is attached to the lower end of the polycrystal and is melted beginning from an upper end of the seed, where a power (P) of the melting apparatus during the first phase (P.sub.1) and during the second phase (P.sub.2) is predetermined at least temporarily in dependence on a temperature and/or geometrical dimensions of crystal material used which comprises the drop and/or the seed and/or the polycrystal.

A single crystal is pulled by the FZ method, in which in a first phase, a lower end of the polycrystal is melted by the melting apparatus, in a second phase, a monocrystalline seed is attached to the lower end of the polycrystal, and in a third phase, between a lower section of the seed and the polycrystal, a thin neck section is formed whose diameter is smaller than that of the seed, where the power of the melting apparatus before the third phase is dynamically adapted in dependence on a position of a lower phase boundary (P.sub.U) between liquid material and solid material on the part of the seed, and where the power of the melting apparatus during the third phase is dynamically adapted in dependence on the position of an upper phase boundary (P.sub.O) between liquid material and solid material on the part of the polycrystal plant.

FZ single crystals are pulled by melting a polycrystal with electromagnetic melting apparatus and then recrystallizing. First, a lower end of the polycrystal is melted; second, a monocrystalline seed is attached to the lower end of the polycrystal and melted beginning from an upper end thereof; third, between a lower section of the seed and the polycrystal, a thin neck is formed whose diameter (d.sub.D) is smaller than that (d.sub.I) of the seed; and fourth, between the thin neck section and the polycrystal, a conical section is formed. Before the conical growth, a switchover position (h) of the polycrystal, the position at which the rate of polycrystal movement relative to the melting apparatus is to be reduced is determined, and the rate is reduced, in amount when the switchover position (h) is reached.

A lasing medium having a tailored dopant concentration and a method of fabrication thereof is disclosed. The lasing medium has a single crystal having a continuous body having a selected length, wherein the crystal comprises dopant distributed along the length of the body to define a dopant concentration profile. In one embodiment, the dopant concentration profile results in a uniform heating profile. A method of fabricating a laser crystal having a tailored dopant concentration profile includes arranging a plurality of polycrystalline segments together to form an ingot, the polycrystalline segments each having dopant distributed, providing a crystal seed at a first end of the ingot, and moving a heating element along the ingot starting from the first end to a second end of the ingot, the moving heating element creating a moving molten region within the ingot while passing therealong.

A lasing medium having a tailored dopant concentration and a method of fabrication thereof is disclosed. The lasing medium has a single crystal having a continuous body having a selected length, wherein the crystal comprises dopant distributed along the length of the body to define a dopant concentration profile. In one embodiment, the dopant concentration profile results in a uniform heating profile. A method of fabricating a laser crystal having a tailored dopant concentration profile includes arranging a plurality of polycrystalline segments together to form an ingot, the polycrystalline segments each having dopant distributed, providing a crystal seed at a first end of the ingot, and moving a heating element along the ingot starting from the first end to a second end of the ingot, the moving heating element creating a moving molten region within the ingot while passing therealong.

The present invention aims at providing an auxiliary heating device for a zone melting furnace and a heat preservation method for a single crystal rod thereof. The auxiliary heating device comprises an auxiliary heater disposed below a high-frequency heating coil inside the zone melting furnace and is formed by winding a hollow metal circular pipe. The winding start end of the auxiliary heater is positioned on the upper part, the winding stop end of the auxiliary heating device is positioned on the lower part, and an upper end part and a lower end part are respectively guided out from the both ends; and a hollow cylindrical heating load is disposed on the inner side of the auxiliary heater, and an insulation part is disposed between the heating load and the auxiliary heater. The present invention can solve the problem of single crystal rod cracking caused by unreasonable distribution of the thermal field and overlarge thermal stress in the growth process of zone-melted silicon single crystals over 6.5 inches.

The present invention aims at providing an auxiliary heating device for a zone melting furnace and a heat preservation method for a single crystal rod thereof. The auxiliary heating device comprises an auxiliary heater disposed below a high-frequency heating coil inside the zone melting furnace and is formed by winding a hollow metal circular pipe. The winding start end of the auxiliary heater is positioned on the upper part, the winding stop end of the auxiliary heating device is positioned on the lower part, and an upper end part and a lower end part are respectively guided out from the both ends; and a hollow cylindrical heating load is disposed on the inner side of the auxiliary heater, and an insulation part is disposed between the heating load and the auxiliary heater. The present invention can solve the problem of single crystal rod cracking caused by unreasonable distribution of the thermal field and overlarge thermal stress in the growth process of zone-melted silicon single crystals over 6.5 inches.