updated 12:44 PM UTC, Nov 23, 2020

MPW 21st Call on 340 nm SOI

CORNERSTONE users are invited to submit designs to MPW #21 with a platform of 340 nm SOI (passives with heaters).

In this call, CORNERSTONE will demonstrate its unique capability of combining e-beam and deep-UV lithography by offering the grating coupler layer patterned by e-beam lithography so that high efficiency apodized grating couplers can be realised with coupling efficiency < 1.5 dB per coupler at a wavelength of 1.55 μm.

The process flow is shown in the animation below*:

*Note that the grating coupler layer will be patterned by e-beam lithography for this call.

A process design kit (PDK) is available using Luceda’s IPKISS software, subject to purchasing the appropriate license. To obtain a copy of the software and a license key, please contact Luceda by sending an email to This email address is being protected from spambots. You need JavaScript enabled to view it., specifying that you require a license for CORNERSTONE PDK usage. The CORNERSTONE PDK is free of charge if you already have a valid IPKISS license.

MPW #21 is charged with the following access rates:

Design Area

Access Cost with Heaters

Access Cost without Heaters

11.47 x 4.9 mm2



5.5 x 4.9 mm2



The sign-up deadline has been extended to Monday 30h November 2020. The mask submission deadline is Friday 18th December 2020.

For more information, full design rules and quick reference design rules, please download the CORNERSTONE 21st Call Design Rules documents and the .GDSII template files.

In order to help you ensure that you comply with the design rules, you can also download a design rule check (DRC) checklist and if you have access to Tanner L-Edit software, a .tdb version of the template containing a DRC file that you can run to automatically find any design rule violations (note that the automatic DRC will not check all of the design rules, so it remains very important to read the design rules in detail).

For any queries, including questions on bespoke processing i.e. custom etch depths etc., please contact This email address is being protected from spambots. You need JavaScript enabled to view it.