Abstract: A process and a device will produce a cylindrical single crystal of semicuctor material with the smallest possible alignment error of the crystal lattice. A process for cutting semiconductor wafers from two or more such single crystals is by means of wire sawing. The process for producing the single crystal is as follows: (a) a single crystal with an alignment error of the crystal lattice equal to at most 1.5.degree.

Abstract: Device for pulling a silicon single crystal 1 includes an element 5 which annularly surrounds the single crystal growing at a crystallization boundary; and the element has a face 6 directed at the single crystal. The element surrounds the single crystal substantially level with the crystallization boundary 2 and has the property of reflecting heat radiation radiated by the single crystal and the similar melt or of generating and radiating heat radiation back to the lower part of the crystal close to the crystallization boundary. There is also a method for pulling a silicon single crystal, in which the single crystal is thermally affected using the element surrounding it.

Abstract: A method for producing a silicon monocrystal has a growing monocrystal kept for a specified dwell time in the specified temperature range of from 850.degree. C. to 1100.degree. C. This dwell time for the growing monocrystal in the chosen temperature range is either greater than 250 min or less than 80 min. A device and a method, in which the cooling rate of the growing monocrystal is to be influenced, has a heat shield which is subdivided into adjacent annular zones between a lower rim and an upper rim. These adjacent zones differ in regard to each's thermal conduction and transparency to heat radiation.

Abstract: A process and an apparatus control the growth of a crystal, which growth is governed by a set of measurable and non-measurable variables. The process includes establishing an on-line simulation software working with a reduced number of variables, the reduction of variables being performed by using a projection algorithm; speeding up the on-line simulation software by generating data banks in which values of off-line precalculated variables are stored; tuning the on-line simulation software by adjusting the results predicted by on-line simulations to the results obtained by off-line simulations and by measurements; and establishing a control loop and controlling at least one of the variables in real time, the control loop using the speeded up and tuned on-line simulation software as an on-line observer.