Technology Platforms

We offer a variety of platforms to suit your applications

With wavelength coverage spanning from the visible spectrum to the mid-infrared, our platforms enable an exceptional range of applications from high-speed datacom to quantum technologies, biosensing, and beyond.

If you require any assistance with design, platform selection, or schedule planning, please contact the CORNERSTONE team directly.

220 nm silicon-on-insulator (passive devices / active devices)

Our team has an exemplary track record in silicon-based modulators having demonstrated several world firsts, including the first 1 Gb/s carrier depletion modulator in 2004, now the industry standard, and the first 50 Gb/s carrier depletion modulator in 2012. In 2020, we demonstrated a fully integrated silicon MZI modulator with CMOS driver operating at 100 Gb/s OOK. More recently in 2025 we demonstrated 200 Gb/s OOK.

Technology
details		 Si etch depths: 70 nm, 120 nm & 220 nm
TiN based thermal phase shifters
4 implantation layers for active device batches
High resistivity handle wafer for improved RF performance (750 ohm.cm)
Performance (TE single mode @ λ = 1.55 µm): Rib waveguide propagation loss: < 3 dB/cm
Strip waveguide propagation loss: < 4 dB/cm
Grating coupler loss: 5-6 dB/grating
Phase shifter efficiency (MZI): < 20 mW/π
Modulator performance (1.8 mm long MZI based carrier depletion):

  • Speed @ 2 V dual drive: > 28 Gb/s
  • Insertion loss @ 2 V dual drive: < 5 dB
  • Extinction ratio @ 2 V dual drive: > 3 dB
Logistics Design area options: 11.47 x 4.9 mm² / 5.5 x 4.9 mm²
Delivery timeframe and cost: Refer to schedule and cost page.

340 nm silicon-on-insulator (passive devices)

Our flexibility enables users to add customised steps into all of our MPW batches. For example, in this platform a user could add e-beam written apodised grating couplers capable of coupling efficiencies of < 1 dB. A user could also add customised etch depths or sensing windows in the top cladding layer.

Technology
details		 Si etch depths: 140 nm & 340 nm
TiN based thermal phase shifters
Performance (TE single mode @ λ = 1.55 µm): Rib waveguide propagation loss: < 2 dB/cm
Strip waveguide propagation loss: < 4 dB/cm
Grating coupler loss: 5-6 dB/grating
Phase shifter efficiency (MZI): < 20 mW/π
Logistics Design area options: 11.47 x 4.9 mm² / 5.5 x 4.9 mm²
Delivery timeframe: < 3 months

500 nm silicon-on-insulator (passive devices)

All of our platforms are supported by an open source process design kit (PDK), which is available to download in GDSII format or is accessible via our software partners.

Technology
details		 Si etch depths: 160 nm & 300 nm
TiN based thermal phase shifters
Performance (TE single mode @ λ = 1.55 µm): Rib waveguide propagation loss: < 3 dB/cm
Grating coupler loss: 5-6 dB/grating
Phase shifter efficiency (MZI): < 20 mW/π
Logistics Design area options: 11.47 x 4.9 mm² / 5.5 x 4.9 mm²
Delivery timeframe: < 3 months

Visible silicon nitride

The visible SiN platform extends the available operating wavelengths of CORNERSTONE’s portfolio into the visible range. This is of particular interest for quantum photonics technologies and biosensing. Both of our silicon nitride platform offer a top cladding opening step to expose the silicon nitride waveguides.

Technology
details		 Platform: 200 nm SiN / 3 μm BOX
SiN etch depth: 200 nm
Performance (TE single mode): Strip waveguide propagation loss: Depends on wavelength
Grating coupler loss: Depends on wavelength
Logistics Design area: 11.47 x 15.45 mm²
Delivery timeframe: < 3 months

Suspended-silicon

The SOI BOX layer becomes highly absorbing at wavelengths above ~3.8 μm. CORNERSTONE’s suspended-Si platform alleviates this problem by locally removing the BOX layer underneath suspended waveguides to extend the transparency of the SOI platform up to ~8 μm.

Technology
details		 Platform: 500 nm Si / 3 μm BOX
Si etch depth: 500 nm, followed by HF etching for undercutting / suspension
Performance (TE single mode): Waveguide propagation loss:
< 1 dB/cm @ λ = 3.8 μm
< 3 dB/cm @ λ = 7.7 μm
Logistics Design area options: 11.47 x 4.9 mm² / 5.5 x 4.9 mm²
Delivery timeframe: < 2 months

Germanium-on-silicon

The Ge-on-Si platform supports wavelengths up to ~14 μm, which makes it well suited for a broad variety of applications including environmental, biological, chemical and pharmaceutical sensing, industrial process control, toxin and contaminant detection, point-of care diagnostics and astrophysics.

Technology
details		 Platform: 3 μm Ge-on-Si (n-type)
Ge etch depth: 1.8 μm
Edge couplers formed by custom dicing process
Performance (TE single mode): Waveguide propagation loss:
< 1 dB/cm @ λ = 3.8 μm
< 1.5 dB/cm @ λ = 6.1 μm
< 3 dB/cm @ λ = 7.6 μm
Logistics Design area: 11.47 x 15.45 mm²
Delivery timeframe: < 2 months

MPW Schedule and Costs