Wafer Bonder Standard Operating Procedure

Updated on 10/14/2014

Note:

• Substrate size: WNF currently has tooling for bonding 4" diameter substrate/wafers. Tooling for other substrate sizes can be purchased from EVG. Piece/die bonding is not allowed with the 4" tooling as it can damage the tooling.

Bond Alignment: EVG620 is used if you require alignment between your wafers.

• Maximum contact force: 10 kN
• Maximum temperature: 550 ºC
• Vacuum: ~0.1 mbar
• Power supply for anodic bonding: 0-2000 V and 50 mA

Contents

1 Cold Start

2 Load Bond Tool and Wafers

2.1 After Alignment on EVG620

2.2 Without Alignment on EVG 620

3 Log-in

4 System Initialization

5 Load Recipe

6 Run Recipe

7 Save The Process Profile

8 Unload Bond Tool

9 Supplemental Documents

1. Cold Start

1. Open the four screw caps.

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2. Open the bond chamber.

3. Check if the pressure disc on the top side in the chamber is for anodic bonding or for direct/thermo-compression bonding/solder bonding.

• See the detail of Bonding Methods.
• If the anodic bonding is required, then the pressure disc is a glass.
• If direct/thermo-compression bonding/solder bonding is required, then the pressure disc is a metal.
• The default setting of the pressure disc is for the direct/thermo-compression bonding/solder bonding.
• If you make the anodic bonding, then please ask the staff for help.

4. If you do vacuum molecular bonding or high alignment accuracy bonding, a bow pin needs to be installed in the center of pressure disc.

• See the detail of Bow Pin in Wafer Bonder Recipes.
• If you need the bow pin, ask the staff for help.

2. Load Bond Tool and Wafers

2.1 After Alignment on EVG620

1. Insert the two guide pins into the two holes of the bond tool.

2. Release a clamp of the carrier tool.

3. Put a graphite plate in the Bond glass.

4. Close the chamber and close the four screw caps.

2.2 Without Alignment on EVG 620

• Note: It is strongly recommended that the bond glass be used even if alignment on EVG620 is not done.
  • If you use the bond glass, then the graphite plate must also be used.
  • If you do not use the bond glass, then the graphite plate do not have to be used.
  • The wafers are likely to be shifted during the process without the bond glass.

1. Pile the wafers up on the Bond tool, and cover them with the bond glass.

• Note:
  • The usage of the separation flags (spacers) entirely depends on the process itself.
  • The following cases generally require the spacers between the 1st and 2nd substrates:
    • The surfaces of the wafers are treated during the bonding process. If you were to hook forming gas, and to remove oxidation from a metal later, you would need the wafers to be separated up to the bond chamber, in order for the gas to penetrate and react with the interface on both wafers.
    • Some pressure inside of cavities of your wafers is encapsulated. If you are trying to remove all air (create a vacuum) within cavities on your wafers or set a certain pressure (for instance 100 mbar) inside of the cavities, you will need a separation between the wafers to allow for better air flow (in or out depending on your goal) between the wafers.
    • In the case of having very bowed/warped wafers where you may be able to trap unwanted gas (air pocket) in the bonding interface, you would want spacing between the wafers to allow the removal of this air pocket.

2. Clamp the bond glass.

3. Put a graphite plate in the Bond glass.

4. Close the chamber and close the four screw caps.

3. Log-in

• Note: If the following EVG Explorer is shown on the screen, then double-click the "EVG CIMFramework" icon to open the log-in window.

1. Type user name and password, and click the "Login" button.

2. The "Jobs" window is opened.

• Note:
  • Overview modules changes from "Locked" to user name.
  • Bond chamber status is shown to be gray, meaning "Disconnected".

3. Right-click on the "BondChamber" icon to open a drop-down menu.

4. Click the "Connect" button.

5. The color of the "BondChamber" icon turns into red.

6. Right-click on the "BondChamber" icon to open a drop-down menu.

7. Click the "Enable" button.

8. The color of the "BondChamber" icon turns into green.

4. System Initialization

1. Click the "System" button in the bottom menu.

2. Click the "Shutdown" button to highlight the "Initialize" button.

3. Click the "Initialize" button.

5. Load Recipe

• See the detail of Recipe Management in Wafer Bonder Recipes.

1. Click the "Recipes" button in the bottom menu.

2. The "Recipes" window is opened.

3. Choose your file.

4. Select a recipe.

6. Run Recipe

1. Click the "Jobs" button in the bottom menu to open the "Jobs" window.

2. Click the "Add Job" button.

3. The "Add Job" dialog box is opened.

4. Open a drop-down menu from the "Recipe" box.

5. Select the bottom line, which is the recipe selected, from the drop-down menu.

6. Type "Lot ID", "Substrate ID", and "Bondchuck ID" if necessary.

7. Click the "OK" button.

8. The recipe starts.

7. Save The Process Profile

1. When the process starts, right-click on the "BondChamber" icon to open a drop-down menu.

2. Choose the "Recorder" from the drop-down menu.

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3. The next drop-down menu is opened. Choose the "Open Recorder".

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4. EVG Recorder is opened.

• Press “Yes” to show the view as last used.
• Press “No” to adjust the settings new.

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5. The process profile starts to be recorded.

• Choose the parameters on the left side.

8. Unload Bond Tool

1. When the process is finished, wait until the top and bottom temperatures are cooled down.

2. When the top and bottom temperatures are cooled down, release the four screw caps and open the bond chamber.

3. Take the bond tool out of the bond chamber, using the carrier tool.

4. Open the clamps on the bond glass, so that the bond glass and the bonded wafers can be taken out of the bond tool.

5. Put the bond tool back to the bond chamber.

6. Close the bond chamber and close the four screw caps.

7. Right-click on the "BondChamber" icon to open a drop-down menu in the "Jobs" window.

8. Click the "Disable" button.

9. Right-click on the "BondChamber" icon to open a drop-down menu in the "Jobs" window.

10. Click the "Disconnect" button.

11. The color of the "BondChamber" icon turns into grey.

12. Click the green user button.

13. The log-in dialog box is opened.

9. Supplemental Documents

• Wafer Bonder Recipes