Süss MJB4

To be read first:

  • Wafers and photoresists exposed on the MJB4 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: a special chuck is available for use with PDMS coated wafers. 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. 24/7 booking/use is possible with CMi+1 extended access.
  3. Reservation names must correspond to operators.


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

I. Introduction

The MJB4 is a mask/wafer aligner for research and development, designed to align and expose wafers up to 4 inch (100 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 i-line (filter installed), meaning only the 365 nm spectral line is absorbed by the resist.

The parallelism between the wafer and the mask is achieved with a semi-automatic procedure of Wedge Error Compensation (WEC). Alignment is achieved with manual micrometer knobs down to a precision of about 0.5 µm. Only the top side alignement option is 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


MJB4 (Mask Aligner)
The MJB4 is a mask to wafer alignement and exposure system. One alignment modes is available: Top side alignment (TSA). The MJB4 is equipped with several options for fine handling of small wafers/chips.

Default illumination setup for exposure: 20 mW/cm2 @ 365 nm (i-line).

Mask holders:

Three different mask holders are equipped with vacuum clamping:

Available chucks:

 Three different chucks for all sizes:

Note: chucks can be used for wafer/substrate thicknesses from 0.1 mm up to 4.0 mm.

Small wafer/chip objectives:

MJB4 is equipped with offset objectives for alignment of small wafer/chips. Minimum separation is 10mm.

11x offset objectives: working distance is 14.1 mm; minimum separation is 10 mm.

Technical Caracteristics:

  • Hg light source with deep UV cutoff (No quartz optics!), default illumination setup: 20 mW/cm2 @ 365 nm (i-line filter installed).
  • Topside (TSA) alignment, using splitfield mode (two objectives).
  • Exposure modes are flood-exposure, proximity, soft contact, and hard contact.
  • Objectives magnification: 5x, 10x
  • Special offset objectives for chip alignment (separation distance down to 10mm).
  • Alignment using fine adjustment screws (alignment accuracy about 0.5µm).
  • XY table movements : X = ± 30 mm Y = ± 30 mm Θ = ± 4°
  • Manual substrate handling up to 100mm diameter.

III. User manuals

IV. Links

V. Pictures gallery