Süss MA6/BA6

To be read first:

  • Wafers and photoresists exposed on the MA6 must be accepted by the technical comittee. CMi staff approval is required before using any non-standard products.
  • Cross-Contamination: Samples must be free of backside contamination. Mechanically unstable metal layers (delamination) are not allowed. Note: PDMS coated wafers are exposed on the MJB4 mask-aligner. Please ask the CMi staff for guidance.

  • Mask should be checked after each working session. Clean with acetone / IPA or with soft tissue to remove any solid or liquid residues.

  • Please immediately inform the CMi staff in case of problems with the equipment.


  1. No booking restrictions.
  2. Reservation names must correspond to operators.


  1. Introduction
  2. Equipement description
  3. Users manuals
  4. Links
  5. Pictures gallery

I. Introduction

The MA6/BA6 is a mask/wafer aligner for research and development, designed to align and expose wafers up to 6 inch (150 mm) diameter. Wafers, coated with photosensitive resists (PR), are exposed through a glass/chrome mask using a short (few seconds) pulse of UV radiation from a mercury (Hg) lamp, with spectral lines at 365nm, 405nm and 436nm. The illumination configuration is broadband (no filter), meaning the three spectral lines are absorbed by the resist.

The parallelism between the wafer and the mask is achieved with au automated procedure of Wedge Error Compensation (WEC). Alignment is achieved with manual micrometer knobs down to a precision of about 0.5 µm. Both top side and backside alignement options are available.

The resolution is limited by light diffraction through the mask opening, and can reach a minimum of about 800 nm with thin PR thickness (< 1 µm).

II. Equipment description


MA6 is a flexible tool with 2 possible configurations:

MA6 (Mask Aligner)
The default MA6 configuration is a mask to wafer alignement and exposure system. Two alignment modes are available: Top side alignment (TSA) and back side alignment (BSA).

Default illumination setup for exposure: 20 mW/cm2 broadband (integrated).


BA6 (Bond Aligner)
The alternative BA6 configuration is used to align two wafers together. Aligned wafers are unloaded from the slide (not recommended), or on the wafer bonding tool (SB6) fixture. More details on the wafer bonding tool can be found here: Süss SB6

Using the BA6 configuration requires a specific training session. Contact the CMi Staff! Users are responsible to switch the tool back to MA6 configuration after using BA6 configuration.

Mask and wafer sizes:

  1. Available wafer chucks:
    • one chuck for 4 inch wafers
    • one chuck for 6 inch wafers
    • one chuck for small wafers/parts
  2. Available mask holders:
    • 7″x7″ mask holder, centered, to use with 6 inch wafers
    • 5″x5″ mask holder, centered, to use with 4 inch wafers
    • 5″x5″ mask holder, adaptable positionning, to use with small wafers/parts

Technical Caracteristics:

  • Hg light source with deep UV cutoff (No quartz optics!), default illumination setup: 20 mW/cm2 broadband (integrated).
  • Backside (BSA) and topside (TSA) alignment. Topside alignment using splitfield (two objectives) or single field as an option for small samples.
  • Exposure modes are flood-exposure, proximity, soft contact,  hard contact, and vacuum contact (2 modes).
  • Objectives magnification (top side): 3.2x, 9x, 25x,
  • Objectives magnification (back side): normal, zoom 2x
  • Alignment using fine adjustment screws (alignment accuracy about 0.5µm)
  • XY table movements : X = ± 10 mm Y = ± 10 mm Θ = ± 5°
  • Manual substrate handling up to 150mm diameter.

III. User manuals

IV. Links

V. Pictures gallery