Siemens Aktiengesellschaft

Harald Kuhn

Rene Stein

Johannes Voelkl

Johannes V&ouml;lkl

Roland Rupp

Dietrich Fischer

Wolfgang Zintl

A method for the sublimation growth of an SiC single crystal, involving heating up under growth pressure, is described. In the method for the sublimation growth of the SiC single crystal, a crucible holding a stock of solid SiC and an SiC seed crystal, onto which the SiC single crystal grows, is evacuated during a starting phase which precedes the actual growth phase and is then filled with an inert gas, until a growth pressure is reached in the crucible. Moreover, the crucible is initially heated to an intermediate temperature and then, in a heat-up phase, is heated to a growth temperature at a heat-up rate of at most 20&deg; C./min. As a result, controlled seeding on the SiC seed crystal is achieved even during the heat-up phase.

Method for the sublimation growth of an SiC single crystal, involving heating under growth pressure

A device for the sublimation growth of an SiC single crystal, with foil-lined crucible. The device for producing an SiC single crystal includes a crucible with a crucible inner zone. Inside this zone, there is a storage area for storing a stock of solid SiC and a crystal area in which an SiC single crystal grows onto an SiC seed crystal. A heater device is arranged outside the crucible. On a side that faces the crucible inner zone, the crucible is lined with a foil of tantalum, tungsten, niobium, molybdenum, rhenium, iridium, ruthenium, hafnium or zirconium. As a result, the crucible is sealed and a reaction between the aggressive components of the SiC gas phase and the crucible wall is prevented.

Device having a foil-lined crucible for the sublimation growth of an SiC single crystal

A seed crystal holder holds a SiC seed crystal while a SiC bulk single crystal is grown on the front surface of the seed crystal. The holder includes a back surface body with a bearing surface for bearing against a back surface of the SiC seed crystal. The holder includes a lateral mount for receiving the back surface body and the SiC seed crystal. The lateral mount has a projection located on an end facing the SiC seed crystal. The SiC seed crystal rests on the projection.

Seed crystal holder with lateral mount for an SiC seed crystal

An &agr;-SiC bulk single crystal is formed from an SiC gas phase by deposition of SiC on an SiC seed crystal. To enable an SiC bulk single crystal of the 15R type to be grown reproducibly and without restricting the seed crystal, the deposition takes place under a uniaxial tensile strength which includes a predetermined angle with the &lsqb;0001&rsqb; axis of the bulk single crystal, so that a rhombohedral crystal is formed.

Method for growing an &agr;-SiC bulk single crystal

A method is described for growing at least one silicon carbide (SiC) single crystal by sublimation of a SiC source material. Silicon, carbon and a SiC seed crystal are introduced into a growing chamber. Then, the SiC source material is produced from the silicon and the carbon in a synthesis step that takes place before the actual growing. The growing of the SiC single crystal is then carried out immediately after the synthesis step. The carbon used is a C powder with a mean grain diameter of greater than 10 &mgr;m.

Method for growing SiC single crystals

A device for producing a silicon carbide (SiC) single crystal contains a crucible having a storage region for holding a stock of solid SiC and having a crystal region for holding a SiC seed crystal. An insert made from glassy carbon is disposed in the crucible. In the method, solid SiC is sublimed as a result of the stock being heated and SiC in the gas phase is generated, which is conveyed to the SiC seed crystal, on which it grows as an SiC single crystal. A heat flux is controlled by an insert made from glassy carbon.

Device and method for producing at least one SiC single crystal

In order to provide in an encapsulated pressurized gas insulated high voltage installation having multiple bus bars an interruption point in line with every current carrying conductor, which can be bridged by a movable conductor part and which forms a gap in a first end position of this conductor part, both conductor ends are surrounded by a shield which defines the gap. The movable conductor part rests in a second end position against an insulating sleeve and is brought through an insulating bearing ring. In the first end position, the movable conductor part is contained in a recess in an end of one of the conductor parts. The movable conductor part has an engagement surface for allowing a tool to grasp the movable conductor part to move it so as to bridge the gap.

Growing community of inventors

Erlangen, Germany

Harald Kuhn