SOP for PZT sol-gel deposition

 

Safety rules

 
These are not authorized official regulations for general PZT sol-gel processing. But, these are valuable rules to protect your safety and everyone should follow these rules when processing PZT in the MSAL micro-fabrication room and LAMP cleanroom. Any personnel who is to run PZT sol-gel processes must be knowledgeable of the following rules
  1. Before you start, read the MSDS of the sol-gel materials carefully (http://www.enma.umd.edu/LAMP/lamp_msds.htm). Keep in mind that the PZT solutions and PZT ceramic films contain carcinogen lead, and can induce acute and chronic health effects.

  2. When the PZT film is baked on a high temperature (>=200 °C) hotplate during the sol-gel process, the vapor from the film contains Pb and PbO, which are very harmful. So check the flow of the fume hood before beginning this step to make sure that the hotplate is in an air-absorbing hood and that the hood is functioning properly.

  3. Always close the panel of the fume hood whenever you are processing. Do not introduce your head underneath a hood whenever PZT materials is processed (either on hot plates or ovens).

  4. Remove any PZT residue before it solidifies.

  5. Handle cracked PZT films very carefully. Dust may be easily generated from a cracked thin film and may be inhaled when you closely examine the film outside the hood. A facemask is recommended if the possibility of film cracking is high in your process. Never blow a cracked PZT film with nitrogen or compressed air outside an air-absorbing hood. Proceed with caution when you blow the cracked film in the hood. Cleaning the cracked film with DI water is recommended before you take the film outside the hood.

  6. 6. If you work with PZT frequently, it is recommended that you have a blood test for lead level every year. Please contact your physician to arrange this kind of test.

  7. For more information concerning lead safety, please visit
http://www.osha-slc.gov/SLTC/lead/. This web page contains essential regulations and documents concerning lead safety issues mandated by the government.
 

Sol/gel storage and handling

 
(Sol-gel solutions are expensive and delicate solutions. Before you begin to handle these solutions, please read the following rules carefully)
  1. Solutions should be stored in the refrigerator when not in use. Leaving the solution at room temperature for extended periods of time may result in degradation.  Make sure that all solutions are clearly labeled with the full name and composition of the solution, your name, the name of your supervisor, the date of introduction. Any unlabeled materials will be discarded without notice by the lab manager.

  2. Please wait a few minutes before opening the bottle after taking it out of the refrigerator. Open the bottle only after it has been warmed up to the room temperature gradually. Please close the bottle tightly as soon as you finish taking the solution out of it. Never leave a bottle open for extended periods of time (i.e. several minutes or more).

  3. Please use new syringes to take the solution out of the bottle. Used syringes must not be used to take the solution from the bottle.

  4. Life time of sol-gel solutions is typically about 6 months to 1 year. It is recommended to change the solution after using about 6 months (at most 1 year). Sol-gel solutions have been changing very slowly even in a refrigerator.
 

Sol/gel process steps

 
 
(Process varies from group to group. These are just general descriptions. For detailed instructions, please consult your group members.)
  1. Spin PZT precursor at 1500-5000 rpm for 15-40 seconds on the sample.

  2. Bake it on 60 –150 °C hotplate for 1-5 minutes.

  3. Bake it on 200-450 °C hotplate for 1-5 minutes.

  4. Anneal it in 500- 700 °C oven for 3-60 minutes.

  5. Repeat steps 1-4 several times, until desired film thickness is attained.
Notes:     Please change the aluminum foil or the clean papers each time you have finished sol-gel processing. Do not leave residual PZT to dry in the spinner. This will introduce particles the next time the spinner is used and may be hazardous to your health.If you have any questions, please contact Lab Manager
 
Prepared by Y. Zhao, last update: February 2002 by L. Henn-Lecordier

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Laboratory for Advanced Materials Processing, University of Maryland - 2009