Positive Photoresist Photoplate PROCESS

Nanofilm CHROME PHOTOPLATES are manufactured with various thickness of Chromium metal and Positive Photoresist thickness. These variations must be considered when establishing the correct process times. This basic process should be used for AZ1518 Photoresist @ 5300 A thickness baked at no less than 100 C for 30 minutes. These plates must be handled in Yellow or Red safelight conditions. The resist is sensitive to blue-ultraviolet light. It is important to keep your process at a constant temperature for consistency (70F, 21C).

Step Description
1. EXPOSURE: The exposure must be determined empirically the first time. The wattage or light output of Ultraviolet varies with various illumination sources. A good starting point with a 200 watt mercury arc source is about 4-8 seconds on a Tamarack contact printer, or 0.7-1.0 second on a Step & Repeat Camera. Make an exposure series to set up the correct exposure times and measure the resulting image dimensions to record the effect the exposure makes on the patterns.
2. DEVELOP: After exposure the plate will be developed In MicroChrome Developer PPD-455 for 30 Seconds. The exposed area will be dissolved. The more the resist is exposed the faster it will dissolve and the larger the exposed areas will become. When setting up a process always keep the development time a constant and vary the exposure to change critical dimensions on the plate.
3. WASH: Wash off the developer thoroughly with either a running DI water wash for 30-60 seconds or spray.
4. ETCH: Place plate in MicroChrome CEP-200 Etchant at room temperatureand agitate gently watching the exposed chrome areas dissolve. When the chrome has cleared; overetch it about 15% then remove it to wash.
5 WASH: Wash the Etchant off the plate thoroughly for 30-60 Seconds using running DI water or Spray.
6 DRY: Dry Photomask with a clean spinning dryer or blow dry.
7. INSPECT: At this time inspect the quality of the mask and measure the critical dimension on the mask to determine if the exposure & process are giving you the results you are expecting.
8. STRIP: Strip the mask for 5 minutes in MicroChrome Stripper PRS-100 at room temperature with gentle agitation.
9. MASK CLEAN: Clean the mask using MicroChrome PCS-605 Photomask Cleaning Solution. Use a clean room FOAM WIPE to gently scrub the Mask.
10. FINAL WASH: Wash in vigorous DI water wash system or spray.
11. FINAL INSPECTION: Inspect mask for Defects, Critical dimensions, Die alignment, etc.
The process is the same with all respects except for the etchant. Use MicroChrome F0-100 Iron Oxide Etchant. The iron oxide etchant is a fuming acid and must be Exhausted. Iron oxide is very Acid sensitive. This Mask should not be cleaned in a strong acid or oxidizing chemical. The Iron will fade when exposed to these chemicals. For any Technical Questions about the Process please call MicroChrome Technology. division of HTA Enterprises at (408) 452-5500.