Page 6 - Nanosystem Fabrication Facility 2018
P. 6

Mask Making Module

                  A      photomask is typically a transparent fused   Laser Direct-Write System
                         glass blank covered with a pattern de ned
                         by chrome metal. A set of photomasks,
                 each de ning a pattern layer in nanosystem fabri-  The laser direct-write system is an effective and
                                                                 efficient pattern generator for mask making. The
                 cation, is fed into a photolithography contact align-  system performs patterning by exposing the
                 er or stepper and individually selected for exposure   photoresist on the mask using a computer-
                 on a silicon wafer. In the case of the contact align-  controlled laser beam. With the use of the raster
                 er, there is a one-to-one correspondence between   scanning writing method, a variety of patterns can
                 the mask pattern and the wafer pattern. With the   be generated. By simply changing the pattern data
                 stepper, however, the pattern is projected and   file (for example, CIF or GDSII format), a new
                 shrunk by  ve times onto the wafer surface.     prototype can be obtained. Due to the system’s
                                                                 excellent write quality and flexibility, microstructures
                                                                 for various applications, such as ASICs, MCMs,
                                                                 MEMS, integrated optics, hybrids, microwave
                                                                 devices, sensors, etc., can be realized.

                                                                                           Electron Beam
                                                                                           Lithography made a
                                                                                           50 nm pattern onto
                                                                                           a quartz wafer

                                                                                           Result of the pattern
                                                                                           after quartz layer
                                                                                           etched (50 nm gap
                                                                                           in between)

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