Patent ID: 6910441

Claim:
Plasma processing equipment comprising: a process chamber; an exhaust system connected to said process chamber so as to exhaust gas from said chamber and thereby create a vacuum within said chamber; a cover covering the top of said process chamber; a workpiece chuck disposed in said process chamber so as to support an object to be processed thereon; a pressure regulating plate disposed at the bottom of said cover above said workpiece chuck in said pressure chamber; at least one elevating mechanism connected to said pressure regulating plate so as to move said plate up and down above said chuck in said process chamber, said elevating mechanism including a fixed block fixed to the top of said cover, a first bracket supported by said fixed block such that the position of said first bracket relative to said fixed block can be adjusted in a vertical direction, a first bearing supported by said first bracket so as to be movable therewith relative to said fixed block, a second bracket supported by said fixed block below said first bracket and mounted to said fixed block so as to be freely movable up and down, a second bearing supported by said second bracket as spaced apart from said first bearing, a cam ring supported so as to be rotatable about a central axis thereof, said cam ring having a top surface confronting said first bearing and a bottom surface contacting said second bearing, and a protrusion at said bottom surface, whereby rotation of said cam ring about the central axis thereof moves said protrusion in and out of contact with said second bearing, and a supporting member connected to and extending longitudinally between the bottom of said second bracket and said pressure regulation plate so as to move with said second bracket and thereby position said pressure regulation plate above said chuck within said process chamber; and a measuring device including at least one visual display operatively connected to said first bearing so as to indicate the relative position of said first bearing, whereby the position of said cam ring can be determined when said first bearing is in contact with the top surface of said cam ring.