Abstract: Monocrystalline semiconductor wafers have defect-reduced regions, the defect-reduced regions having a density of GOI-relevant defects within the range of 0/cm2 to 0.1/cm2 and occupy overall an areal proportion of 10% to 100% of the planar area of the semiconductor wafer, wherein the remaining regions of the semiconductor wafer have a significantly higher defect density than the defect-reduced regions. The wafers may be produced by a method for annealing GOI relevant defects in the wafer, by irradiating defined regions of a side of the semiconductor wafer by laser wherein each location is irradiated with a power density of 1 GW/m2 to 10 GW/m2 for at least 25 ms, wherein the laser emits radiation of a wavelength above the absorption edge of the wafer semiconductor material and wherein the temperature of the wafer rises by less than 20 K as a result of irradiation.

Abstract: Monocrystalline semiconductor wafers have defect-reduced regions, the defect-reduced regions having a density of GOI-relevant defects within the range of 0/cm2 to 0.1/cm2 and occupy overall an areal proportion of 10% to 100% of the planar area of the semiconductor wafer, wherein the remaining regions of the semiconductor wafer have a significantly higher defect density than the defect-reduced regions. The wafers may be produced by a method for annealing GOI relevant defects in the wafer, by irradiating defined regions of a side of the semiconductor wafer by laser wherein each location is irradiated with a power density of 1 GW/m2 to 10 GW/m2 for at least 25 ms, wherein the laser emits radiation of a wavelength above the absorption edge of the wafer semiconductor material and wherein the temperature of the wafer rises by less than 20 K as a result of irradiation.

Abstract: Monocrystalline semiconductor wafers have defect-reduced regions, the defect-reduced regions having a density of GOI-relevant defects within the range of 0/cm2 to 0.1/cm2 and occupy overall an areal proportion of 10% to 100% of the planar area of the semiconductor wafer, wherein the remaining regions of the semiconductor wafer have a significantly higher defect density than the defect-reduced regions. The wafers may be produced by a method for annealing GOI relevant defects in the wafer, by irradiating defined regions of a side of the semiconductor wafer by laser wherein each location is irradiated with a power density of 1 GW/m2 to 10 GW/m2 for at least 25 ms, wherein the laser emits radiation of a wavelength above the absorption edge of the wafer semiconductor material and wherein the temperature of the wafer rises by less than 20 K as a result of irradiation.

Abstract: In a process for producing silicon semiconductor wafers, a silicon single crystal is pulled using the Czochralski method and is processed to form semiconductor wafers, a ratio V/G of pulling rate V and axial temperature gradient G at a growth front during the pulling of the single crystal being controlled in such a manner that agglomerated vacancy defects above a critical size are formed in the single crystal, the agglomerated vacancy defects, in a region of the semiconductor wafer that is of relevance to electronic components, shrinking during production of the components such that the size in this region no longer exceeds the critical size. Silicon semiconductor wafers with agglomerated vacancy defects in the relevant device region preferably contain agglomerated vacancy defects having an inner surface which is at least partially free of an oxide layer and a size of less than 50 nm.

Abstract: Monocrystalline semiconductor wafers have defect-reduced regions, the defect-reduced regions having a density of GOI-relevant defects within the range of 0/cm2 to 0.1/cm2 and occupy overall an areal proportion of 10% to 100% of the planar area of the semiconductor wafer, wherein the remaining regions of the semiconductor wafer have a significantly higher defect density than the defect-reduced regions. The wafers may be produced by a method for annealing GOI relevant defects in the wafer, by irradiating defined regions of a side of the semiconductor wafer by laser wherein each location is irradiated with a power density of 1 GW/m2 to 10 GW/m2 for at least 25 ms, wherein the laser emits radiation of a wavelength above the absorption edge of the wafer semiconductor material and wherein the temperature of the wafer rises by less than 20 K as a result of irradiation.

Abstract: In a process for producing silicon semiconductor wafers, a silicon single crystal is pulled using the Czochralski method and is processed to form semiconductor wafers, a ratio V/G of pulling rate V and axial temperature gradient G at a growth front during the pulling of the single crystal being controlled in such a manner that agglomerated vacancy defects above a critical size are formed in the single crystal, the agglomerated vacancy defects, in a region of the semiconductor wafer that is of relevance to electronic components, shrinking during production of the components such that the size in this region no longer exceeds the critical size. Silicon semiconductor wafers with agglomerated vacancy defects in the relevant device region preferably contain agglomerated vacancy defects having an inner surface which is at least partially free of an oxide layer and a size of less than 50 nm.

Abstract: An SOI wafer, includes a substrate made from silicon, an electrically insulating layer with a thermal conductivity of at least 1.6 W/(Km) and a single-crystal silicon layer with a thickness of from 10 nm to 10 ?m, a standard deviation of at most 5% from the mean layer thickness and a density of at most 0.5 HF defects/cm2. A process is for producing an SOI wafer of this type, in which a substrate wafer made from silicon is joined to a donor wafer via a layer of the electrically insulating material which has previously been applied. The donor wafer bears a donor layer of single-crystal silicon, with a concentration of vacancies of at most 1012/cm3 and of vacancy agglomerates of at most 105/cm3. After the wafers have been joined, the thickness of the donor wafer is reduced in such a manner that the single-crystal silicon layer having these properties is formed from the donor layer, this single-crystal silicon layer being joined to the substrate wafer via the layer of electrically insulating material.

Abstract: A silica glass crucible is produced by a) providing a porous amorphous silica glass green body, which is infiltrated with at least one substance that promotes crystallization of a silica glass crucible, b) drying the infiltrated silica glass green body, c) filling the green body with a metal or semimetal, and d) heating the filled green body for a period of from 1 h to 1000 h to a temperature of from 900 to 2000° C. to form at least a portion of silica crystalline phase. The process may be continued by further heating to melt the metal or semimetal and pulling a single crystal from the melt.

Abstract: An SOI wafer, includes a substrate made from silicon, an electrically insulating layer with a thermal conductivity of at least 1.6 W/(Km) and a single-crystal silicon layer with a thickness of from 10 nm to 10 &mgr;m, a standard deviation of at most 5% from the mean layer thickness and a density of at most 0.5 HF defects/cm2.

Abstract: A silica glass crucible is produced by

Abstract: A process for producing a silicon single crystal has the crystal being pulled using the Czochralski method while being doped with oxygen and nitrogen. The single crystal is doped with oxygen at a concentration of less than 6.5*1017 atoms cm−3 and with nitrogen at a concentration of more than 5*1013 atoms cm−3 while the single crystal is being pulled. Another process is for producing a single crystal from a silicon melt, in which the single crystal is doped with nitrogen and the single crystal is pulled at a rate V, an axial temperature gradient G(r) being set up at the interface of the single crystal and the melt, in which the ratio V/G(r) in the radial direction is at least partially less than 1.3*10−3cm2min−1 K−1.

Abstract: A process for producing silicon wafers with low defect density is one wherein a) a silicon single crystal having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 is produced by molten material being solidified to form a single crystal and is then cooled, and the holding time of the single crystal during cooling in the temperature range of from 850.degree. C. to 1100.degree. C. is less than 80 minutes; b) the single crystal is processed to form silicon wafers; and c) the silicon wafers are annealed at a temperature of at least 1000.degree. C. for at least one hour. Also, it is possible to prepare a silicon single crystal based upon having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 and a nitrogen doping concentration of at least 1*10.sup.14 /cm.sup.3 for (a) above.