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Silicon Photonics


MPW runs

VTT has been offering low-cost access to its 3 µm SOI waveguide platform via multi-project wafer (MPW) runs since 2014. This service was launched under ePIXfab with the support of the EU project ESSenTIAL. 1-2 runs will start each year. The next run is scheduled to start in February 2018 and the design freeze for this run is in January.

How to participate

VTT requires a design kit license agreement (DKLA) to be signed before gaining access to the MPW process development kit (PDK). The DKLA document can be downloaded from here. Please send two signed copies to the address indicated. You may also send VTT a scanned copy of the signature page to gain faster access to the PDK.

When you wish to participate in a run, please send a freeform email to stating the needed design size, process modules and amount of chips. We will then follow with an official quote.

Chip offering

The MPW runs offer two design sizes: 20 mm x 20 mm and 5 mm x 10 mm. The basic price includes either one chip of 20 mm x 20 mm design, or 8 pcs of 5 mm x 10 mm design. Option to purchase more of identical chips is also offered.

The present MPW costs are summarized below:


5x10 mm design
(8 chips)

20x20 mm design
(first chip)

Delivery of additional 20x20 mm chips
Passive chips (no metals or implantation)6000 €6000 €/chip+2500 €/chip
Chips with metallization & implantation11 000 €12 000 €/chip+5000 €/chip
Fixed starting cost per order


​2000 €


MPW process modules

The MPW offering is currently split into two process modules, namely passive and active. The passive module is mandatory as it provides the basic waveguide structures, and dielectric films for cladding and anti-reflection coatings. The passive module alone is suitable for realizing e.g. multiplexing or filtering functionality where active tuning is not required. Inclusion of the active module allows for more advanced functionalities such as active tuning and hybrid integration.

Passive module

The two main optical waveguide types provided in the MPW runs are the single-mode rib waveguide (40% etch depth) and the multi-mode strip waveguide (95% etch). The rib waveguide's broad-band single-mode operation is useful for creating mode-strip sections and directional couplers, for example. Total internal reflection (TIR) mirrors can be used for sharp turns in rib-waveguides.

Strip waveguides enable the realization of extremely compact waveguide circuits and components, including small multi-mode interference (MMI) couplers and µm-size Euler-bends. With proper design the optical power can be kept in the fundamental mode and the design kit includes converters to switch between the two waveguide types as needed.

Active module

The optional active module adds both metals (Al, Au) and silicon implantation (p, n) to the process. This allows far more complexity to be added to the photonic circuits than with the passive module alone. Implanted heaters enable thermal tuning that is efficient and fast. The two metals support electrical wiring, flip-chip integration of e.g. laser chips on SOI chip, as well as reflectors to create resonators or to enhance echelle grating performance.