Abstract: An apparatus for controlling the fluid flow rate through a fluid transmission conduit is disclosed. A first set of resistors and a second set of resistors are connected in full bridge fashion and placed in contact with a separate measurement conduit in fluid communication with the fluid transmission conduit. A signal from the measurement conduit proportional to the fluid flow rate therein is sent to a computer. The computer is operative to actuate a control valve in response to the signal. The control valve is disposed upstream from the measurement conduit inlet in the fluid transmission conduit. The computer is also enabled to perform an autocalibration routine of the flow control apparatus that a yields a control accuracy of better than 1 percent.

Abstract: An apparatus and a method for coating electronic elements in particular semi-conductor wafers, circuit boards and the like are provided where the flow of the gaseous coating material is directed so that a contamination of the elements through deposited remains in the reaction tube from previous coating processes can be largely avoided. In addition, an integrated apparatus for cleaning the coating apparatus with a plasma is provided. In an in-situ cleaning method, a plasma generated with microwaves is fed into the reaction tube and the inner surfaces of the reaction tube are cleaned by dry etching.

Abstract: A system for the heat treatment and doping of semiconductor wafers or the like has a heating system which can be moved axially over a quartz pipe by means of a linear shifting means, in which quartz pipe the materials to be treated are arranged. The ambient atmosphere is at least partially removed from the quartz pipe in the process, after which the semiconductor wafers are subjected to the desired treatment atmosphere; the heated oven is thereafter moved over the quartz pipe to complete the treatment.