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Center of MicroNanoTechnology CMi

Atomic Layer Deposition BENEQ TFS200
Presentation of the equipment


ALD


I. Introduction CMI

The tool Beneq TFS200 is an ALD (Atomic Layer Deposition) system done for the deposition of thin dielectric or metallic layers on wafers from 100 mm up to 200 mm as well as on piece of wafers. The Atomic Layer Deposition (ALD) technique is recommended for thin layers (max 100 nm) and/or layers with a high level of conformality. The deposition is done under vacuum (around 5 mbar) from chemical precursors.


II. Equipment description CMI

The equipment is composed of: The equipment is driven by a software interface but some manual operations are requested for each deposition:

Schematic of the gas line of the ALD tool
Schematic of the gas line of the ALD tool

Chamber

The chamber is compatible with 3 different reactors: one reactor for the manual loading/unloading, one reactor compatible with the plasma/loadlock options and one reactor for multi wafers deposition. The chamber can be heat up to 500C.

Loadlock

The use of the loadlock system is mandatory only for deposition process including plasma. But the use of the system is recommended for the deposition of TiN in order to avoid the contamination of the layer with O.


III. Deposition mechanisms CMI

The deposition is done in 4 steps as described below:
  1. The first precursor (precursor 1) is pulsed to the reaction space and reacts at the surface of the sample by chemisorptions.
  2. The reaction chamber is purged with inert gas (N2) and the excess of precursor 1 is removed
  3. The second precursor (precursor 2) is pulsed to the reaction space and reacts with the precursor 1 at the surface of the sample, the result of the reaction produce a byproduct.
  4. The reaction chamber is purged with inert gas (N2) and the excess of precursor two and the byproducts of the previous reaction are removed.
The steps 1 to 4 are reproduced until we get the requested thickness of the layer. An illustration of these 4 steps is done with the deposition of Al2O3 from the Tri-Methyl Aluminum (TMA) and water (H2O).

Step 1
Introduction of the precursor 1 (TMA) in the reaction space



Step 1
Chemisorption of precursor 1 (TMA) at the Si surface with radical OH




Al(CH3)3 (g) + Si-O-H (s) -> Si-O-Al(CH3)2 (s) + CH4
Step 2
Purge with N2



Step 3
Introduction of the precursor 2 (H2O) in the reaction space



Step 3
Reaction of the precursor 2 (H2O) at the surface




2 H2O (g) + Si-O-Al(CH3)2 (s) -> Si-O-Al(OH)2 (s) + 2 CH4
Step 4
Formation of a mono layer of Al2O3
And purge with N2



After 3 cycles



Al(CH3)3 (g) + Al-O-H (s) -> Al-O-Al(CH3)2 (s) + CH4
2 H2O (g) + O-Al(CH3)2 (s) -> Al-O-Al(OH)2 (s) + 2 CH4


IV. Available layers at CMi CMI

6 different layers can be deposit at CMi. The main process parameters are summarized in the table I. The thickness of the layer is directly proportional to the number of cycle excepted for Ru, where we have a delay of around 500 cycles before having the first atomic layer deposited.


Precusor 1Temp. (C)Precusor 2Temp. (C)Chamber temperature (C)Deposition rate (A/cy)
Al2O3TMARTH2ORT2001.22
TiO2TiCl4RTH2ORT2000.42
HfO2TEMAH80H2ORT2001.0
SiO2BTBASRTO3RT3001.0
Pt
(CpMePtMe)75
O2
RT
280
0.5




How to use the system

I. Login CMI




1. Login on the PC zone  4



2. Press the button "Control" to open the window "Control" on the Beneq laptop



3. Login on Beneq laptop (if it's not already done)
  1. Login: oper
  2. Password: oper
Control screen view

Control screen view


II. Setting of the chamber and precursor temperatures CMI

On the control window, you click on the black number corresponding to the reactor temperature and to the precursor temperature and you enter the temperate requested for the deposition (see below). It takes roughly 30 min for the reactor to get 200C from room temperature and 1 hour for the hot sources.


Al2O3
  • Chamber: 200C
  • Liquid precursor 2 (TMA): room temperature
Control screen view

Control screen view
HfO2
  • Chamber: 200C
  • Hot source 1 (TEMAH): 80C
TiO2
  • Chamber: 200C
  • Liquid precursor 3 (TiCl4): room temperature
SiO2
  • Chamber: 300C
  • Liquid precursor 4 (BTBAS): room temperature
Pt
  • Chamber: 280C
  • Hot source 2 (CpMePtMe): 75C



III. Wafer loading CMI

    1. Press on the load lock button (bottom right)

    2. Press on load-lock vent and wait until the load lock is at atmospheric pressure

    3. Open the load-lock door

    4. Load your wafer/samples

    5. Close the load-lock door and press on load-lock pump down

    6. Checking of the wafer position

    7. Open gate valve

    8. Manual transfer of the wafers in reactor with the substrate loader

    9. Move up the substrate lifter

    10. Move back the substrate loader in home position

    11. Move down the substrate lifter

    12. Move up the holder lifter

    13. Close the gate valve


    After 5 min check the chamber and reactor pressure, if the pressure of the chamber pressure is below 7 mbar, the loading is not correct. Move down and up 2 times the holder lifter.

     

    If there is no improvement, unload the wafer/sample and restart the procedure.

     

     

    DO NOT START THE DEPOSITION IF THE PRESSURE DIFFERENCE BETWEEN THE CHAMBER AND THE REACTOR IS

    BELOW 6 MBAR


      Reactor and load-lock in standby

      Reactor and load-lock in standby



      IV. Starting a recipe CMI

        1. Go to the window Control

        2. Select your recipe in the recipe folder

        3. Press compile and download the recipe

        4. Press start batch and follow the instructions (open precursor valves)

        5. At the end of the process close the hand valve if requested


          Al2O3
          Open liquid precursor 1 (H2O)
          Open liquid precursor 2 (TMA)
          Liquid precursors
          gas lines
          HfO2
          Open liquid precursor 1 (H2O)
          Hot source 1 is already open (TEMAH)
          TiO2
          Open liquid precursor 1 (H2O)
          Open liquid precursor 3 (TiCl4)
          SiO2
          Open liquid precursor 4 (BTBAS)
          Gas precursor (O3) is already open
          Pt: Hot source 2 is already open (CpMePtMe) / gas precursor (O2) is already open



          Control screen view

          Control screen view




          V. Wafer unloading CMI


            1. Go the window Load lock

            2. Open the gate valve

            3. Move down the holder lifter

            4. Move up the substrate lifter

            5. Transfer of the substrate loader in the reactor

            6. Move down the substrate lifter

            7. Move back the substrate loader in home position

            8. Close the gate valve

            9. load-lock vent / wafer unloading

            10. Open the load-lock door and take your wafers

            11. Close the load-lock door and then clic on load-lock pump down

            12. wait for the message "Load-lock vacuumize. Close load-lock lid. Press yes to continue"  and press yes

            13. wait for the message "Load-lock vacuumize. Gate valve can be opened. Press yes to continue" and press yes



              VI. logout CMI

              Once all your depositions are finished, the equipment come back in idle mode:

                1.Switch off the heating of the hot source

                2. Fill in the notebook

                3. Log out on the PC zone 4