EV Si to Si Alignment
Electronic Visions 620
Function Overview: Optical lithography contact/proximity aligner-bonder
- 4 exposure modes: contact, vacuum contact, hard contact and proximity
- frontside and backside alignment
- 10X objectives (100X total)
- bonding chucks for anodic bonding, thermal compression bonding and fusion bonding.
- minimum resolution in dark field = 1.0um line and <1um contacts
- minimum resolution in clear field = 2um line and 2um contacts
- 4" wafers, 5" masks
Special Notes or Restrictions:
- This machine allows most materials
- See Materials section of our website for details
- Clean front and back of mask before use
- Clean mask every one to five wafers
Operating Procedures for Bonding Si to Si
- Leave key ON
- Check that the Lamp Power Supply is ON
- PC Power is left on
- Do not lean on the system at any time.
- Enable "evalign"
- You need to make sure that the chuck is centered as much as possible to the mask holder. You can start by putting the micrometers x, y, and theta to the mark we have made on the micrometers.
- Click icon ev620
- OR if already there click on login and enter "620" for name and enter "620" for password.
- Initialization begins.
- Follow instructions on screen (arrow indicates a machine instruction)
- ->Move <tray out>
- Double click on the process you want.
are standard processes so only change exposure time, alignment
other necessary changes. Do not save the changes..
- Standard programs are: Top side align; bottom align; Si-Gl bond; Si-Si bond.
- Click "Run"
- ->Save changes? NO (use them for your process only, do not change the program permanently)
- ->Start> (initialization begins)
- ->Insert Bondtool>
- Insert Bond Tool into the holder with the writing "Bond Chuck Top" up and facing towards you.
- Bond Tool - use clean gloves, do not touch chuck part. . (Separation flags may not be used, but if they are check that they will slide over a wafer without catching)
- Goes in on top of bond tool frame.
- Hold by feet and lower it in.
- Press CONTINUE
|Process=Anodic (for Si-Si)||Mask Holder=5" Wafer=4"|
|Process Mode=crosshairs (overlay, normal)|
|Exposure mode=no exposure||Exposure time=0|
|Contact Mode=normal||Delay time=0|
|Proximity gap um=0||Interval= 0|
- ->Load Top Wafer>
- Load Bond Glass and the first wafer on the chuck using large ruler.
- Position Bond Glass with writing up and on the right side ("top").
- Load 1st wafer on the bond glass with the structured side down
- Position them up against the ruler (use large ruler for bonding) wafer flat side to the right
- Don't forget to remove ruler!
- ->Move <TRAY IN>, (no flags used)
- ->Check the flags,they must be out (confirm with continue).
- ->Please wait>
- ->Adjust microscope>
to reach targets
- Use Micrometer spindles (x axis, y axis and theta) to center the bond glass ( align to corner marks)
- Press "Scan Optic" in the "Position-Menu" and you can move the microscopes with the joystick in x y and z direction (small motions give slower responses). For x and y push forward back or right or left, for focus rotate clockwise or counter clockwise.
- To adjust for rotation use the micrometer screw ( since the wafer is not yet attached by vacuum)
- Press "CONTINUE" when targets have been found and focused (to attach first wafer with vacuum)
- Move the crosshair with help of the Trackball.
- Move the cursor with the trackball to a crosshair, then press the left button and you can move the crosshair.
- Crosshair size and color can be changed when "control button" is selected
- For Overlay: You can freeze an store the picture of the adjusted marks of the mask. (adjust tmarks and press "continue")
- Later when you want to adjust the substrate you see a shadow from he stored mask marks on the screen (you can change the intensity with the overlay regulator) and you can adjust the substrate to the shadow of the mask.
- Press <CONTINUE>
- ->Please Wait
- ->Move <TRAY OUT>
- Load second wafer
- => Load bottom wafer on the bond glass with ruler (the structured side up).
- Position them up against the ruler wafer flat side to the right
- Press <CONTINUE> to activate wafer vacuum, check vacuum
- Don't forget to remove ruler
- ->Move <tray in>
- ->PREADJUST SUBSTRATE>
- Use micrometer spindles (x axis, y axis and theta) to center the bond glass (align to corner marks)
- Press <CONTINUE>
- ->Insert Separation Flags>(if flags are to be used)
- Press <CONTINUE>(wec is performed)
- ->ADJUST STAGE>and press
sep/cont to move into contact
- Note: the screen may go out of focus, just adjust it if this happens.
- Align second wafer (Glass to Si) using the 3 micrometer spindles (x axis, y axis and theta)
- ->CLAMP WAFER>
- Clamp the wafer by pressing down and rotating the two clamps.
- The wafers will be pressed together. Because they are already in contact, you should not get any offset.
- Press <CONTINUE> when wafer is clamped
- ->Remove Bond Tool>
- The whole bond tool can now be picked up and transported to the bonder for anodic bonding.
- Press <CONTINUE>
- ->Move <tray out>
- ->Press CONTINUE> or EXIT>
- Pressing continue will start the process again
- Pressing exit will end the process
- ->END OF PROCESS>
- Change Chuck back to standard alignment chuck
- Lift out Bond Tool Frame and replace mask holder
- Select Park. Move tray in? Click on yes and move the tray in.
- Leave Key ON
- Leave PC Power on.
- Click on Log off
- Disable "evalign"
Button Description Limits Choose Scan Optic Scan Optic
To move with the split field microscope. In addition you see the minimum, maximum and actual value of the left and the right microscope in X, Y and Z direction. With "Store Optic Pos" you can store the actual optic position. With "Load Optic Pos" you can load a stored optic position.
Recipe To set process data during the process Controls To change the cross data and overlay intensity (in case of topside alignment you do not have a cross.) continue Usually acknowledges previous choice or that what is on screen is done. Also may push <ENTER> button for same result (button with arrow down and to the left) enter Confirms data entry Track Ball Used for PC control Joystick Adjust split field microscope in X and Y (right and left, forward and back)and to focus (rotate clockwise or counterclockwise). Speed controlled by slow or fast movements. L/R: To change between left and right objective Sep/Cont: To change between separation and contact Undo: If you have a problem press "Undo" to go one process step back, and follow instructions on screen. Stop: To stop the process Exit: To leave the process WEC Force: Check pressure during WEC only, cover weight can be adjusted.(0.4 barr) Exposure Force:
Check pressure during align phase (0.5 barr).
Chuck Weight: Is actual pressure during WEC (270 -300 mbarr) Hard Contact: When hard contact mode is selected you can adjust N2 pressure (0.5 barr)
Lamp can not be restarted when key is turned on.