Siltronic Ag

Walter Heuwieser

Karl Mangelberger

Michael Skrobanek

Timo Mueller

Gudrun Kissinger

Martin Weber

Andreas Sattler

Georg Raming

Thomas Schroeck

Dieter Knerer

Alfred Miller

Werner Schachinger

Juergen Vetterhoeffer

Masamichi Ookubo

Timo Müller

Thomas Schröck

Jürgen VETTERHÖFFER

Single silicon crystals having a resistivity of ≤20 mΩcm are pulled by the Czochralski process from a melt, by a method of pulling a first section of a neck at a first velocity whereby the diameter of a first section of the neck, with respect to the diameter of a seed crystal, tapers at a rate of ≤0.3 mm per mm neck length to a diameter of not more than 5 mm;

Method for pulling a single crystal of silicon in accordance with the Czochralski method

A method produces semiconductor wafers of monocrystalline silicon. The method includes: pulling a cylindrical section of a single silicon crystal from a melt contained in a crucible, wherein the oxygen concentration in the cylindrical section is not more than 5×10atoms/cm; subjecting the melt to a horizontal magnetic field; rotating the crucible at a rotational velocity and in a rotational direction during the pulling of the cylindrical section of the single crystal; and removing the semiconductor wafers of monocrystalline silicon from the cylindrical section of the single crystal. An amount of rotational velocity, averaged over time, is less than 1 rpm and the rotational direction is changed continually and the amplitude of the rotational velocity before and after the change in the rotational direction is not less than 0.5 rpm and not more than 3.0 rpm.

Method for producing semiconductor wafers of monocrystalline silicon by pulling a single silicon crystal from a melt contained in a crucible and continually changing the rotational direction of the crucible

Single crystal semiconductor ingots are pulled from a melt contained in a crucible by a method of controlling the pulling the single crystal in a phase in which an initial cone of the single crystal is grown until a phase in which the pulling of a cylindrical section of the single crystal is begun, by measuring the diameter Dcr of the initial cone of the single crystal and calculating the change in the diameter dDcr/dt; pulling the initial cone of the single crystal from the melt at a pulling rate vp(t) from a point in time tuntil a point in time t, starting from which the pulling of the cylindrical section of the single crystal in conjunction with a target diameter Dcrs is begun, wherein the profile of the pulling rate vp(t) from the point in time tuntil the point in time tduring the pulling of the initial cone is predetermined by means of an iterative computation process.

Method for pulling a single crystal composed of semiconductor material from a melt contained in a crucible

Single crystal semiconductor wafers comprise oxygen and an n-type dopant, and are produced by a process comprising providing a silicon melt containing n-type dopant in a quartz crucible, the melt having an initial height hM;

Method for producing a semiconductor wafer of monocrystalline silicon, device for producing a semiconductor wafer of monocrystalline silicon and semiconductor wafer of monocrystalline

A semiconductor wafer comprising single-crystal silicon has defined concentrations of oxygen, nitrogen and hydrogen; the semiconductor wafer further contains BMD seeds having a density averaged over the radius of not less than 1&#xd7;10cmand not more than 1&#xd7;10cm; surface defects having a density averaged over the radius of not less than 1100 cm; and BMDs, whose density is not lower than a lower limit of 5&#xd7;10/cm. The semiconductor wafers are produced by a process which enables obtention of the required ranges of concentrations of oxygen, nitrogen, hydrogen, BMD seeds, and BMD's.

Semiconductor wafer made of monocrystalline silicon, and method for producing same

The invention relates to a silicon wafer having a radial variation of oxygen concentration of less than 7%, determined over the entire radius of the silicon wafer. The wafers are produced in the Pregion with rotation of crystal and crucible in the same direction, and in the presence of a horizontal magnetic field of defined intensity.

Silicon wafer with homogeneous radial oxygen variation

Semiconductor wafers composed of monocrystalline silicon and doped with nitrogen contain an OSF region and a Pregion, wherein the OSF region extends from the center radially toward the edge of the wafer as far as the Pregion; the wafer has an OSF density of less than 10 cm, a BMD density in the bulk of at least 3.5&#xd7;10cm, and a radial distribution of the BMD density with a fluctuation range BMD/BMDof not more than 3. The wafers are produced by controlling initial nitrogen content and maintaining oxygen within a narrow window, followed by a heat treatment.

Semiconductor wafer composed of monocrystalline silicon and method for producing it

Silicon semiconductor wafers are produced by:

Method for producing semiconductor wafers composed of silicon having a diameter of at least 450 mm, and semiconductor wafer composed of silicon having a diameter of 450 mm

Growing community of inventors

Stammham, Germany

Walter Heuwieser