Abstract: Wafer boats for the plasma treatment of disc-shaped wafers, in particular semiconductor wafers for semiconductor or photovoltaic applications, and a plasma treatment apparatus for wafers are described. A wafer boat comprises a plurality of first carrier elements which are positioned parallel to one another, wherein each first carrier element has a plurality of carrier slits for receiving the edge of a wafer or wafer pair, and a plurality of second carrier elements which are positioned parallel to one another, which are each electrically conductive and have at least one recess for holding the edge region of at least one wafer or one wafer pair. An alternative wafer boat comprises a plurality of electrically conductive plate shaped carrier elements, which are positioned parallel to one another and which are less than half as high as the wafers to be received, wherein the carrier elements each have on their opposing sides at least three carrier elements for receiving wafers.

Abstract: According to a method and an apparatus for determining absolute plasma parameters in unsymmetrical radio frequency (RF) low-pressure plasmas, a radio frequency discharge current generated in a plasma reactor is measured in the form of analog signals at a portion of the reactor acting as earth electrode, the analog signals are converted into digital signals, and the desired plasma parameters are evaluated from the digital signals by means of a mathematical algorithm. The apparatus includes a meter electrode which is insulatedly positioned in a flange or recess of the reactor wall which acts at least as part of the earth electrode. The method and apparatus may be used with respect to plasma etching in the technical field of the semiconductor technology.

Abstract: In accordance with the method of the present invention, the radio frequency discharge current generated in a plasma reactor is measured in the form of analog signals at a portion of the reactor acting as an earth electrode. The analog signals are converted into digital signals, and plasma parameters are evaluated from the digital signals by means of a mathematical algorithm.