Laser Pattern Writer

Solid State Physics Laboratory (sspl), Delhi, has set up a Mask Fabrication Facility, which is capable of fabrication of photo mask up to minimum feature size of one micron. The facility is self-contained with class 100, 1000 and 10,000 clean rooms, all utilities and services put in position with a provision for future expansion.

Photo mask is very important and critical component of any device processing technology. The quality and yield of the final device depends upon the quality of the mask used to transfer the electrical equivalent artwork commonly known as layout, onto the substrate. A set of mask, depending upon the nature of application and complexity of the device/circuit is required to fabricate the device. Therefore, the photo mask fabrication is not the simple translation of artwork on a set of specially prepared glass/quartz plate but a very precise technology in itself. More complex circuits like current Pentium processors require mask set comprising more than hundred perfectly aligned/stacked mask set to complete the device processing. The facility is equipped with specially designed fire detection and gas flooding type fire protection system.

The mask processing facility at present uses a laser pattern writer to write the layout pattern on the chrome blanks of size 2.5X 2.5 to 6X 6 but provision has been made to commission an e-beam pattern writer at a later date. Facility has complete wet and dry processing equipment line, which is being optimally used depending upon the complexity/feature size and edge definition requirement of the mask user. The facility also has provision for equipping it with mask repair, mask duplicator, CD measurement and auto inspection system in the near future to convert it to a complete mask fabrication.