FIELD: plasma treatment of semiconductor plates. SUBSTANCE: device used for flexible clamping of electrode in supporting unit has supporting member with its lower surface facing the plate to be treated in reaction chamber, electrode with its lower surface facing the plate and upper surface of outer edge facing lower surface of supporting member, and clamping member engageable with outer edge of electrode; clamping member provides for flexible clamping of electrode in supporting member. Method for device assembly and for plate etching by means of mentioned electrode is given in description of invention. EFFECT: improved plenarily from electrode center to periphery with critical dimensions maintained within desired limits. 29 cl, 8 dwg
