Si-photonics waveguides manufacturability using advanced RET solutions

Abstract

Si-Photonics is the technology in which data is transferred by photons (i. e. light). On a Photonic Integrated Circuit (PIC), light is processed and routed on a chip by means of optical waveguides. The Si-Photonics waveguides functionality is determined by its geometrical design which is commonly curved, skew and non-Manhattan. That is why printing fidelity is very challenging on photonics patterns. In this paper, we present two different Optical Proximity Correction (OPC) flows for Si-Photonics patterning. The first flow is regular model based OPC and the second one is based on Inverse Lithography Technology (ILT). The first OPC flow needs first to retarget the input layout while the ILT flow does support skew edges input by tool design and does not need any retargeting step before OPC. We will compare these two flows on various Si- Photonics waveguides from lithography quality, run time and MRC compliance of mask output. We will observe that ILT flow gives the best Edge Placement Error (EPE) and the lowest ripples along the devices. The ILT flow also takes into account the mask rules so that the generated mask is mask rule compliant (MRC). We will also discuss the silicon wafer data where Si-Photonics devices are printed within the two different OPC flows at process window conditions. Finally, for both OPC flows, we will present the total OPC run time which is acceptable in an industrial environment.