Ask the Staff

Hi Aida,

Our Staff Scientist, Aamer Mahmood, spins the AZ9260 resist at 3000 rpm for 60 seconds to receive 6,000 angstroms of resist. His hot plate Soft Bakes are 110 degrees C. for 10 minutes. He exposes one resist layer on the MA6 for 60 seconds. When double coats of AZ9260 are required, a 120 second exposure is needed. The intensity on our MA6 mask aligner (14mW/cm2) is measured using a intensity monitor calibrated for the 405nm i-line. This would result in a exposure dose of 840 mj/cm2 for 6000 angstroms of AZ9260 and 1680mj/cm2 for 12,000 angstroms. Aamer uses the AZ400K developer at a (1:2 developer to DI water ratio) for quicker develop times. With the developer solution ratio of 1:2 in an immersion bath, 2 - 3 minutes are required to fullly develop the exposed areas. Hot plate Hard Bakes are 120 degrees C. for 30 minutes. These longer bake times are necessary to reduce the sticking issues between your substrate and photomask while using contact mask aligners.

The AZ 9200 series of positive photoresists are high-resolution, thick resists capable of the type of process you mentioned. From the manufacturers Material Data Sheet, 11.0 um of resist thickness can be obtained with a single spin process using 1700 - 2000 rpm's for 30 - 60 seconds. Thicker resist requirements would result in a double coating process. Hot plate Soft Bakes from 90 - 110 degrees C. for 120 - 180 seconds are noted when using a g-line stepper process. The preferred developer is AZ400K. The manufacturer recommends a (1:4 developer to DI water ratio) for best results. For a resist thickness of 10 um, doses of 1500 - 2100 mj/cm2 are required for proper g-line stepper exposures.

Your exposure times will vary depending upon the final resist thickness and the mask aligner of choice. MJB3 mask aligners are calibrated for 10mW/cm2 and the MA6 is calibrated for 14mW/cm2. Exposure times of 2-3 minutes will be needed for proper exposures of AZ9260 in your thickness range.

Mike Courtney