Abstract: Method for providing a proportioned gas flow of triisobutylaluminum from liquid triisobutylaluminum having isobutene admixed therein. The liquid is preheated sufficiently to evaporate the isobutene therefrom but leaving the triisobutylaluminum substantially in liquid phase. The vaporized isobutene is separated from the liquid triisobutylaluminum, and subsequently the triisobutylaluminum from which isobutene has been removed is evaporated. Preheating is conducted at a temperature of 30.degree.-40.degree. C. The evaporation of liquid triisobutylaluminum is conducted at a temperature of 40.degree.-60.degree. C.

Abstract: Method and apparatus for the batchwise simultaneous treatment of several substrates by chemical vapor deposition. The method is carried out in a closed system and before the deposition treatment, the substrates are subjected to a cleaning treatment in the same system.

Abstract: A process for halide etching of a semi-conductor substrate in the presence of water. Etching is realized in a reaction vessel. The process steps comprise filling of the reaction vessel with a first gas to a first pressure and subsequently filling the reaction vessel with a second gas to a second pressure after which the substrate is left in the reaction vessel for several minutes to obtain the etching required. One of the gases is HF and the other of the gases is water vapor. The etching is conducted at sub-atmospheric pressure, preferably below 50 Torr.