Transparent Ring for Low Angle Pellicle Inspection
Original Publication Date: 1980-Jul-01
Included in the Prior Art Database: 2005-Feb-13
Masks used for semiconductor manufacturing must be free of defects and kept clean at all times, since both defects and dust particles can cause additional defects in the finished product. Defects can be inspected for during the creation of the mask and prior to its use. Dust particles, however, can occur at any time during the creation of the mask or during the use of the mask. To prevent dust particles from falling on and adhering to the mask surface, pellicles are attached to the mask. To secure the pellicle, a transparent ring is affixed directly to the mask, and the pellicle is stretched over the surface of the ring. A second locking ring is deposited over and above the pellicle to secure the stretched pellicle on the lower ring.