Stepper 2 (Autostep 200) - Piece vs. Wafer Programming Differences
In this section you can find instructions how to expose first/second layer on a full wafer and on the wafer piece using a single centered reticle.
Exposing full wafers:
First layer
Follow instructions for job programming. Create the job with passes needed for exposing different layers on the wafer. Select the proper chuck, attach the shim if needed. Load the chuck with a wafer on the stage. Type on the keyboard EX or EXEC Job name\Pass name1. Wait for the stage to stop moving. There is no need for aligning. The pattern will be centered to the center of wafer. This is your first layer. Microscope inspect after developing to make sure exposure looks good.
Second layer
Select the proper chuck, attach the shim if needed, for your wafer. Load the chuck with a wafer on the stage. Edit your job and make sure information for the Job name\Pass name is correct. On the keyboard type command EX or EXEC Job name\Pass name2. Wait for the stage to stop moving. Start manual alignment. Find your right alignment mark on the right monitor, and align cross on the right objective to the right alignment mark. Press "A" and switch to the left objective. Align left objective to the left alignment mark. Repeat process until you are satisfied with alignment. You should see the same amount of the light between lines. Make sure your alignment looks good on the right objective. Press EXEC on the keyboard. Microscope inspect after developing to make sure second layer is aligned well to the first layer.
Exposing wafer pieces:
Exposing wafer pieces is more complicated than wafer substrates. The main reason for this is that wafer pieces are usually small, they are not as flat as wafers are. Resist on a wafer piece is not coated as uniformly as it is on the wafer. The first challenge for wafer pieces is getting the first layer at the right place. This requires some skills regarding loading and aligning the wafer piece, as well as entering correct parameters in the job (key offset, pass shift). Document bellow explains exposing a first layer on the wafer piece if using a single centered mask plate.
1. First layer
Please find detailed instructions how to expose the first layer on a wafer piece using a single centered mask plate.
Single centered mask - Piece 1st lithography Autostep200 *
2. Second layer
Please find detailed instructions how to expose the second layer on a wafer piece substrate using two different mask plates:
- Single centered mask plate (for wafer pieces with orientations BL (bottom left), and BR (bottom right):Single centered plate Piece - 2nd Litho Autostep 200 *
- Multi layered mask plate (for wafer pieces with either orientation ( BL or BR): Quads mask plate Piece - 2nd litho Autostep 200 *