Abstract: The present invention relates to a method for reducing structural damage to the surface of monocrystalline aluminium-nitride substrates, according to which the substrate undergoes thermal treatment in a crucible in an autoclave, during which treatment the aluminum-nitride substrate is sublimated in the damaged regions of the surface of the substrate and is removed. The method is used to prepare the surface of monocrystalline aluminium-nitride (AlN), in particular the aim of the invention is to eliminate, or at least significantly reduce near-surface structural damage to the monocrystalline material caused by mechanical processing. The invention also relates to aluminium-nitride substrates that are treated in this way.

Abstract: The present invention relates to aqueous suspensions containing 30 to 95 wt.-% metal carbide particles and a dispersant, and to a process for coating substrates using said aqueous suspensions. The invention also relates to the coated substrates that can be produced by the process according to the invention and to the uses thereof.

Abstract: The present invention relates to a method for the production of crystal layers or bulk crystals of group III nitride or of mixtures of different group III nitrides by means of precipitation, at a first temperature T1 in a first temperature range, from a group-III containing fused metal on a group-III-nitride crystal seed placed in the fused metal or on a foreign substrate placed in the fused metal, with the admixture of nitrogen in the fused metal at a pressure P. With the method a solvent additive is added to the fused metal which increases the conversion rate of group III metal to group III nitride in the fused metal. The fused metal runs through at least one temperature cycle with a first and a second process phase in which cycle the fused metal cools after the first process phase from the first temperature to a second temperature T2 below the first temperature range and at the end of the second process phase is heated from the second temperature back to a temperature within the first temperature range.

Abstract: The present invention relates to a method for increasing the conversion of group III metal to group III nitride in a fused metal containing group III elements, with the introduction of nitrogen into the fused metal containing group III, at temperatures?1100° C. and at pressures of below 1×108 Pa, wherein a solvent adjunct is added to the fused metal containing group III elements, which is at least one element of the following elements C, Si, Ge, Fe, and/or at least one element of the rare earths, or an alloy or a compound of these elements, in particular their nitrides.

Abstract: The present invention relates to a method for increasing the conversion of group III metal to group III nitride in a fused metal containing group III elements, with the introduction of nitrogen into the fused metal containing group III, at temperatures?1100° C. and at pressures of below 1×108 Pa, wherein a solvent adjunct is added to the fused metal containing group III elements, which is at least one element of the following elements C, Si, Ge, Fe, and/or at least one element of the rare earths, or an alloy or a compound of these elements, in particular their nitrides.

Abstract: The present invention relates to a method for the production of crystal layers or bulk crystals of group III nitride or of mixtures of different group III nitrides by means of precipitation, at a first temperature T1 in a first temperature range, from a group-III containing fused metal on a group-III-nitride crystal seed placed in the fused metal or on a foreign substrate placed in the fused metal, with the admixture of nitrogen in the fused metal at a pressure P. With the method a solvent additive is added to the fused metal which increases the conversion rate of group III metal to group III nitride in the fused metal. The fused metal runs through at least one temperature cycle with a first and a second process phase in which cycle the fused metal cools after the first process phase from the first temperature to a second temperature T2 below the first temperature range and at the end of the second process phase is heated from the second temperature back to a temperature within the first temperature range.