Edwin Jan Klein - Universiteit Twente

5.2. Fabrication and mask design of laterally coupled
resonators
5.2.1 Fabrication
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Fabrication
The most basic fabrication process is that which is used for the fabrication of devices
based on laterally coupled resonators. Only contact lithography is used to define the
waveguides and typically only two layers, a core and a cladding layer are required to
build the device. This makes the process highly suitable for the testing of new MR
based devices because a typical fabrication run can be performed in less than a week.
The only critical step in the process lies in the accurate definition of the small coupler
gaps typically associated with laterally coupled resonators. Good control of the
lithography is therefore highly important.
Figure 5.1. Process flow with the major fabrication steps required to fabricate laterally
coupled Si3N4 microring resonators.
The process flow with the major fabrication steps used to fabricate a laterally coupled
resonator is shown in Figure 5.1. As a substrate a thermally oxidized 4 inch silicon