To be read first:
- Working with small chips: There is a risk of crashing the writehead on the sample, inducing major equipment downtime, if the standard operating procedure for loading is not followed accurately. Make sure to call the CMi staff if you are unsure how to proceed!
- Working with small chips: minimum chip size 5mm * 5mm.
- The equipment is sensitive to airborne solvent contamination on optical elements, and is equipped with charcoal filters. Always double-check that the window bay is closed when leaving the tool!
RESERVATION RULES AND BOOKING FEES POLICY:
- Booking: maximum 10 time slots allowed at any time.
- Users with long CAD conversion times (>1 hours) are encouraged to book overnight or during the weekends.
- Reservation names must correspond to operators.
- Billing : 6 minutes + processing time.
- This equipment is subject to penatly fees in case of user’s no-show.
The MLA150 (named DLA in the past) is a new generation Mask-Less Aligner developed by Heidelberg Instruments GmbH in Germany. This system allows researchers to quickly print a design, without the need to order or produce a mask, by exposing the photoresist with a UV laser (375 or 405 nm) focussed and scanned over the wafer.
The MLA can convert CAD-generated layout of standard file formats (.gds, .cif, .dxf,…), then align (top- and backside) and expose it on a substrate within a few minutes.
The resolution is limited by the photoresist, wavelength and resolving power of the optics (NA, depth of focus), and can reach a minimum of about 1 um with thin photoresist (PR) thickness (< 1 µm).
The MLA150 is an intuitive tool. Wafer dimensions are automatically detected and the laser is directly focussed at the center of the wafer after loading. Users should set only two parameters:
- Dose: controls the dose [mJ/cm2]. Keep in mind that the light source and exposure conditions are not the same as with a mask aligner so optimal dose and exposure results will be slightly different.
- Defocus: defines where the focus is done. If set to zero, focus is done at the top of the resist, a positive defocus will shift the focus downwards inside the resist (range: -10 .. +10, 10 being a shift of about 6 microns).
The MLA150 system is equipped with:
- Exposure source: 405 nm or 375 nm laser diodes
- 3 cameras: overview for quick crosses localization, macro and micro for automatic detection of alignment crosses
- Optics for top-side and back-side alignment
- Real time autofocus
- Stage system, position control with interferometers, chuck with vacuum for various substrate sizes
The MLA150 system offers the following specifications:
- Minimum feature size: 1 um
- Uniformity: <100 nm
- Alignment accuracy: <500 nm (down to <200 nm depending to the size of the design)
- Maximum substrate size: 220 mm x 220 mm (9″x9″)
- Maximum exposure area: 150 mm x 150 mm
- Designs compatibility: cif, gdsii, dxf , gerber
- Writing time (100 mm wafer): 25 minutes for a full wafer in quality mode, 12 minutes in fast mode.
N.B. The exposure time may vary depending on the complexity of the design