Abstract: A vacuum device. The vacuum device includes a frame, a first glass substrate, a second glass substrate and a plurality of metal spacers. The second glass substrate is connected to the first glass substrate by the frame. The plurality of metal spacers are disposed between the first glass substrate and the second glass substrate. The plurality of metal spacers are made of an alloy whose thermal expansion coefficient is between 8×10−6 and 9×10−6, and the plurality of metal spacers are bonded to the first glass substrate and the second glass substrate by sealing glass.

Abstract: A method and apparatus for measuring a wafer position on a lower electrode in a plasma etching device are disclosed herein. A wafer is generally placed on a lower electrode in a process chamber of a plasma etching device. Such a wafer (i.e., semiconductor wafer) generally comprises a front side and a back side. A differential pressure gradient between the front side and the back side of the wafer is determined, and thereafter, a position of the wafer on the lower electrode can be measured utilizing the differential pressure gradient.

Abstract: A planar fluorescent lamp having a first panel, a second panel, a glass rim, a venting tube, and a set of electrodes. Fluorescent layers are formed on both the first panel and the second panel. The glass rim is mounted on edges of the first and second panels. A recess and a gap are formed in the glass rim; the recess is used for placing the electrodes while the gap is reserved for installing the venting tube. The first panel, the second panel, and the glass rim are so arranged so that a cavity is formed thereby. The cavity is vacuumed via the venting tube and mercury vapor and inert gas are then introduced into the cavity.