MJB4 - Internal Resources

MJB4 Staff Page (Restricted)

Overview

General Description

The Suss MJB4 is a contact mask aligner for exposing pieces up to 100 mm wafers with 3, 4, and 5 inch photomasks.

Specifications

• Light source: 

  • 350 W Mercury Short-arc lamp, Micro Lens (MO) optics for sharper edges.

  • Output wavelengths: 350-450 nm, covering the g-line (436 nm), h-line (405 nm), and i-line (365 nm)

  • Exposure uniformity: ±2.5% over 100 mm round.

• Output intensity: 

• Maximum resolution, under optimum conditions with 1 μm thick resist:

  • Soft contact: 2.0 μm

  • Hard contact: 1.0 μm

  • Vacuum contact: <0.8 μm

• Alignment accuracy, under optimal conditions:

  • Top Side Alignment: 1 μm, <0.5 μm with "SUSS recommended wafer targets"

  • Infrared Alignment (not equipped, would require purchase of BSA options): 2 μm

• Travel:

  • Alignment stage travel:

    • X & Y: ±5 mm, resolution of 0.1 μm

    • Theta: ±5°, resolution of 4x10^-5°

  • Topside Microscope Travel:

    • X: ±40 mm

    • Y: +25 mm to -55 mm

    • Theta: None with single field,  ±4° with optional splitfield microscope (would need to be purchased)

• Usable masks and substrate:

  • Substrate Sizes: 5 x 5 mm up to 100 mm wafer

  • Substrate thickness: Up to 4 mm

  • Mask size: 2" x 2" up to 5" x 5"
    
    
    

Sample Requirements and Preparation

Samples should be cleaned and prepared with further processing steps in mind, as well as conditions that enable good adhesion between the substrate and photoresist.

For the aligner itself, samples must be free of resist on the substrate backside. If any resist or residue is present, it should be removed with the following process:

1. Put on a clean, new pair of solvent gloves.

2. In a solvent hood (with appropriate PPE), squirt some acetone on either a cleanroom wipe, a cleanroom swab, or a polyester wipe.

3. Hold the sample firmly with tweezers, or if necessary, with clean, double gloved hands. Note that holding with hands is only recommended if the gloved hand has touched NOTHING since being put on.

4. Carefully wipe the wafer backside with the wipe/swab, making sure not to touch the substrate front side. Acetone can wick into resist, and so should only areas of resist to be removed.

5. Repeat as necessary to remove any residue.

Proper Alignment of Wafer Pieces

The MJB4 uses a self leveling stage to automatically planarize the substrate chuck against the photomask when contact mode is engaged. This works well for wafers, but this mechanism must be considered when using small substrate pieces. When exposing on a single piece, be sure to place it directly in the center of the chuck. To further assist in proper planarization, place 3 spare substrate pieces evenly separated towards the edges of the chuck.

Standard Operating Procedure

Written SOP

Training / SOP Video