PECVD
PECVD Procedure
edited from what the MRC has posted (http://www.mrc.utexas.edu/index.php/nnin/processequipment/94). NTS, 11/30/2012. NTS, 6/2013.
Prep
1. Log on to the tool using the LabAccess terminal. Hopefully you remembered to reserve time to account for: ramping temperature if needed, pre-cleaning (before and after temp ramp), priming, depositing, and post-cleaning.
(2. Log into the system software, if not already logged in.)
3a. The chamber will be in ON or STANDBY or RUN mode, and which chamber is selected will be at the top of the monitor.
3b. If you want to change the chamber, change the system to ON mode and select the chamber to be used. “Utilities”=> “Select Active Chamber”=> chose either the left or right chamber”. There may be a delay while the tool closes valves and such.
3b1. In ON mode only the ON button will be highlighted. In STANDBY mode both the ON and STANDBY button will be highlighted. Similarly for RUN mode. To change from STANDBY/RUN to ON, click the ON button. To change from ON to STANDBY (or RUN) click on the STANDBY (or RUN) button.
3b2. The chambers are set up how they look, with PECVD being the left chamber.
3c. Change the chamber to STANDBY mode if not already done.
4. Vent chamber : “Utilities”=> “Vent”
[Note that Step 5.2 “Chemical Chamber” requires you to look at other steps. Process in numeric order.]
5. Clean the chamber before the first process is started. Wipe the walls and any quartz wafer holders with IPA. Wipe the stage with IPA.
> PECVD Cleaning procedure (from Ricardo on 11/28/2012 [M/D/Y]):
> 1. Physical chamber: Wipe side walls, shower head, chuck/stage, and seal.
> Use IPA or DI. Do not use IPA if chuck is hot.
> Do not clean stage til it is under 80C, and if it is near there (and <80) use wipe moistened with DI and quick, light wipes.
> 2. Chemical chamber: Run desired O2 clean for desired time.
> 3. chemical residual (optional): If you have a problem with residual chemical depositing on your sample (I would think O2 because that's what just ran but Ricardo just said that chemicals can get stuck in the shower head), wipe shower head with DI moistened wipe (quick, light motions again).
6a. Pump down the chamber to low vacuum
6b. Firmly hold the lid to the chamber down and evacuate the chamber by choosing: “Utilities”=> “Pump Chamber”=> “LoVac”. Once the chamber is under low vacuum you may stop holding the lid down. System status will now be ON & STANDBY (or ON & RUN).
6c. Unless you have 6 foot arms, you will have to start the pump down from the console and then quickly move over to the chamber and press the lid down.
6d. Hold the lid down (at minimum) til the chamber status reads 2000 mT.
7a. Run a cleaning recipe. See Steps 12-14.
7b. The cleaning recipe may vary by application. The clean room’s recommendation: 10 to 30 minute oxygen clean, Pressure = 200mTorr, O2=18sccm, power = 300W. They have cleans in the sysmon folder on the computer.
7c. The Bank group has a couple cleans in our recipe folder. In general, use these.
8a. Run a pre-deposition/prime of your recipe. Length varies by recipe and deposition time.
8b. See Steps 12-14.
Load Sample and Setup Recipe
9. Vent chamber : “Utilities”=> “Vent”
10. Place your sample/s in the chamber. If you can, place it slightly forward (toward you) of center, as it may slide backward a little during deposition.
11. Pump down the chamber to low vacuum
12. To edit a recipe choose: “Process”=>”Edit”, now choose the recipe from the list. Edit the recipe and save it before exiting.
13a. To load a recipe choose: “Process”=>”Load”, now choose the recipe. The loaded recipe will show in the Process box at the lower right.
13b. Click READY on the lower bar to prepare the chamber to run the loaded recipe.
Run Recipe and End Use
14a. Run the loaded recipe by clicking the RUN button at the lower right.
14b. Most recipes have an initial step that will check for correct chamber statistics before running the recipe, so you can start recipes before the chamber is ‘at specs’ and it should wait to start until the temperate, pressure, etc. are correct. However, always check the recipe (see Step 12) to be sure.
14c. Some recipes will vent the chamber automatically. Be aware of what the recipe will do. If you have to run a 2 hour clean at 9pm (after your deposition), it may behoove you to make sure the clean leaves the chamber under low vacuum as the last step (see Step 14d). Ricardo said in that case, it is OK to run the clean and then leave for the night. The chamber will be in ON & RUN.
14d. As with any clean room tool, be aware that you are logged in to the tool for a limited amount of time. If you are running a long process, you may have to login to lab access and reset (lengthen) the time you are logged into the machine for.
14e. To my knowledge, only the RF power requires you to be logged into the tool. Ramping temperature and operating the low vac pump does not require LabAccess. However, if you’re not logged into LabAccess another user might think you forfeited your time slot.
15. Once your recipe is finished, vent the chamber, remove your sample/s, and place in another sample/s (if using the same recipe) til you have processed all samples.
16. Pump down the chamber to low vacuum.
17. Run a chamber clean that is appropriate for whichever process you just ran. Use Step 7 as a guideline. See Step 14c.
18a. Close Gate Valve. Always close the gate between the chamber and the pumps before logging off or when leaving the system idle for over 10 minutes. (When the gate is left open pump oil back streams into the chamber [Ricardo said this isn’t an issue].)
18b. Choose: “Utilities”=>”Close Gates”. Or turn the tool to just ON mode.
18c. The exception is when you run a long clean and leave for the night.
(19. Log off of the system software, I don’t think this is done. – Do not do this!)
20a. Log off of the tool using the LabAccess terminal. Stay logged in if a long clean is running.
20b. If you have a long clean and someone is scheduled to start after the clean finishes, try to sync up your LabAccess so your time will expire when the clean finishes.