Overlay Process Mode

Contents

1 Find Alignment Marks on The Top Wafer

2 Load Bottom Wafer

3 Alignment between The Top and Bottom Wafers

1. Find Alignment Marks on The Top Wafer

1. When the next message shows up, click the "L" (left) or "R" (right) microscope button to activate the left or right microscope.

2. Find left and right alignment marks on the top wafer on the screen, using the joystick.

• Note:
  • If the joystick is kept pressing left or right, then the microscope moves x direction.
  • If the joystick is kept pressing up or down, then the microscope moves y direction.
  • If the joystick is rotated, then the focus is adjusted.

3. Click the "Continue" button.

4. When the next message shows up, click the "Continue" button to take a snapshot of the alignment marks on the top wafer.

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2. Load Bottom Wafer

1. Move the tray out manually.

2. When the tray is in position, the next message shows up.

3. Load a bottom wafer in the same manner as the top wafer. The following messages show up:

1. Insert Ruler And Press <Continue>
2. Insert Bond Glass And Press <Continue>
3. Load Bottom Substrate And Press <Continue>
4. Remove Ruler And Press <Continue>
5. Move Tray In

3. Alignment between The Top and Bottom Wafers

1. When the tray is in position, the following message shows up.

2. Find alignment marks on the bottom wafer, and pre-align them with those on the top wafer, using three X-, Y-, and theta-stage moving micrometers.

• Note: Do not move the microscopes.

3. Click the "Continue" button.

4. Insert the spacers, and click the "Continue" button.

5. Wait until wadge compensation is done.

6. Remove the spacers, and click the "Continue" button.

7. Align the marks on the bottom wafer with those on the top wafer, using three X-, Y-, and theta-stage moving micrometers.

• Note: No not move the microscopes.

8. Click the "Continue" button.

9. Insert the spacers again, and click the "Continue" button.

10. Check the alignment.

• If it is OK, then click the "Continue" button.
• If not, then click the "Undo" button, and repeat the alignment procedure.