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ASML Training, Mahnaz

 

Coming to Asml training:

Yoo-hoo, you passed the emulator training…

Our asml is  5500/60 model

* 5:1 reducing stepper

    * Maximum die width = 18 mm; Maximum die height = 22.6 mm (actual maximum die is slightly smaller)

    * I-line (365 nm) with NA (numerical Aperture  0.54)

    * alignment accuracy of 60 nm.

    * Typical resolution to 0.45 microns

      I have been able to do .3 um isolated lines.

    * 5" quartz  reticle masks, 90 to 120 mil thick.

       Wafer thickness has to be less than 1.1 millimeter.

 

The two reticle prealignment (snow flakes) are necessary to prealign the reticle to the machine frame.

The reticle alignment marks and the wafer global alignment marks are required for the through the lens

Global wafer to reticle alignment.

The wafer alignment marks (PM or XPA marks) need to be exposed on the wafer before the system can do the second layer.

We do encourage the use of the XPA marks. 

The same global alignment marks are used throughout all the processing layers.

When a metal layer is deposited over a planarizing layer or a thick layer of oxide...etc then is recommended to remove the planarizing layer locally above the wafer global alignment marks.

 This can be achieved by using PF image as part of a clear out layer by using the  combi reticle.

 

 Equipment training:

First  step is Emulator training, this is file writing.

 

After your file has been checked You are ready for the next step Equipment training....

Welcome .......

 

You need:

Your file saved on a floppy diskette.

Have your wafers ready for exposure at the time of training, this means,

YES oven, and spun with resist, are DONE.  

Not sure, what resist to use?  Talk to me before hand? We have Shipley 955-.7 (I line) and Shipley 3612(G/I line) resists.

Bring your mask if you are doing any layer besides PM or XPA marks.

 

 SMIF boxes and Reticles:

There are three smif boxes

SNF has one, we can open and use it

One smif box has the combi reticle in it. Can use it but can not open at all (ASML).

One other SMIF box can not touch (ASML).

 

 Wafers:

 

No scribe on the back of wafers, if needed you can scribe the flat side up and clean wafers in nonmetal bench before proceeding with your process. (assuming is si wafers and no metal on them)

 

EBR (edge bead removal) is MUST Top and bottom both. Cleanliness is very critical, if the backs of wafers are dirty; it   can cause hot spot and change of focus on your wafers and others after you.

SVGtrack 2 should be your first choice to spin the wafers that will go to ASML.

 

Back of the wafers has to be free of any resist, scratches and residue if not, needs to be cleaned with q-tips and acetone and then wafers have to go to Spin rinse dryer in the litho area.

(I will show it during training).

All wafers should be run through the SRD (spin rinse dryer) before exposure on ASML regardless of if you have cleaned them or NOT.

There is a black cassette with three black pin designated for the ASML wafers that are going through SRD. We will cover this during training.

 

 

 

 

Flatness check is a must

It is wise to establish the stress in the beginning of the run and with addition of each layer. I have noticed that is specifically true about the double sided polish wafers. We have Flexus-2320, we strongly suggest if you are doing multilayer or thick depositions check the wafer stress at each level starting with first layer.

Please find the information here and ask for training, takes about 30 minutes. I will not be able to cover it during the Asml equipment training.

https://snf.stanford.edu/SNF/equipment/characterization-testing/flexus-2320


we use the Granite stone for quick test . (I will show it during training). The wafers can be warp (convex or concave).  ASML and I trying to establish the spec for this.

 

Addition of every layer will add more stress to the wafer; it is your responsibility to check the wafer flatness at each step before using the ASML.  Warp wafers has to be planned (Linda, Gary and Mahnaz) and ran during the day only then we will accept the responsibility of getting the tool stuck. Getting the tool stuck is time consuming and expensive so you need to do your part. If  wafers get stuck in the system due to being  warp  or , dirt ( residue, scratches on the back of wafers) and stress around the edge of wafers, all the time that system is down will be charged to your account.  And you will be up for community service, No exception.

If you have any question you are welcome to talk to John Bumgarner.

 

 

Quick Wafer Flatness test for ASML

This test is done on the Rock/Granite/table in the characterization room.

 

Clean the Right side of the table with IPA and wipes.

 

Put your wafer on the table/granite if the wafer SLIDE, the wafer is FLAT if not then is NOT flat. If the wafer is not flat you should wait and check with staff ( Gary and I) before committing your wafers.

Please do not take a chance by running nonstandard wafers that are not FLAT, damaged, stressed  or something on the back of wafers and you are not able to take it off for any reason off hours, the system will shut down and I will take your name off the system and every one will hate you.  For wafers of this nature we can discuss the issue and try to process it and during the day when both ASML and us are here (there is always hope).

 

I have put two wafers on the Granite/ table which are labeled FLAT and NOT FLAT for you to see the difference.

 

 

The system gets checked daily for particles on the chuck By  Gary and Mario If we encounter issues with particles on chuck, and we see you are not following the procedure for cleanliness    we will simply disqualify you and you will be up for community service.

 

Do not reset the system under any circumstances, shut down the system and report the problem on badger.

Give detail information of what happened and the status of the reticle and any wafers stuck in the system.

                                                              The information is critical to us to  know in order to reset the system.

 

 

Few kind reminders:

Need negative or nonstandard resist, talk to me.

Keep the table across from the Asml clean and clutter free.

Make sure to take the metal cassette back to svgcoat/dev.

Make sure to not leave your reticle in the SNF smif box.

Make sure to close the SMIF box.

The lost reticles will go into a bin labeled litho masks underneath the table with hotplates.

The reservation on the tool belongs to ASML from 7:30 till 2 pm Tuesday through Friday.  If you like to use it check with Makoto, Gary, Mario and I.

When ASML need to do a demo and needs longer tool time, I will communicate that,  way in advance.

 

Need to do something nonstandard, talk to us before doing anything.

We will help you to run the nonstandard wafers during staff hours.

Stressed wafers, warped wafers  or any other  problem has to be scheduled during staff hours.

If the system get stuck and we realize that your wafers were problematic your privilege will be taken  away and you will do community service.

 

 

Here's the updated information on AMSL zero layer targets. 

The depth etch for front side on pm and xpa marks in si is 1200 A

The depth etch for 3D in si is 1600 A

Measure the etch depth do not assume!!!!!


I have also included a section in Process Modules under Dry etching that has links to the one step process modules.  This may be the best place to refer people.

Here's the link;

https://spf.stanford.edu/SNF/processes/process-modules/etching/dry-etching/asml-zero-level-global-target-marks

 

 

And here's a copy of the summary table

Etcher

Program

Etch Time

Total Time
 per Load

Cleanliness
Level

Total Wafers
per Load

amtetcher

 Program #4

5:00 min

30 mins

semi-clean

24

p5000etch

CHC POLY ETCH

0:27 secs

 20 mins

 semi-clean

1 (8 per pump
down), 50 max

lampoly

 Program #1

 0:20 secs

 30 mins

 semi-clean

 25, cassette to cassette

drytek1

 Poly Etch

 0:30 secs

 20 mins

contaminated

1

drytek2

 Poly Etch

0:30 secs

20 mins

 semi-clean

6


Send folks to the wiki?

-Nancy

 

Please note that for top side you need to etch down 1200A

For back side is 1600A.

Please make sure that you measure and confirm the etch rate depth.

 

Here is another data on etch from Dario:

 

Hi Mahnaz,

Here is some data that I gathered on the etching of ASML alignment marks in the P5000 etcher.  I had two wafers with ASML alignment marks.  I ran both in the P5000 in chamber C with recipe CH.C POLY ETCH.  The times were as follows:

wafer 1: 36 sec etch, 0 sec overetch
wafer 2: 39 sec etch, 0 sec overetch

The results as measured in the zygo profilometer were as follows:

wafer 1: 1460 +- 30 angstrom
wafer 2: 1550 +- 20 angstrom

Both wafers came out reasonably close to the target of 1600 angstrom.  From now on I will be using an etch time of 40.5 seconds, as I believe this is likely to hit the target exactly.
Dario

 

Mahnaz

8/6/13

 

 

 

 

 

 

 

 

 

 

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