DesignRules

Design Rules

WG

• 3 um trenches for 200 um S-bends keep bending losses minimal
• Put 50 um trench around Verniers and alignment markers

VC

• 8 um x 8 um, 50 um separation
• No VC around verniers, so verniers have a chance of being exposed after substrate removal
• Detailed design rule, particularly for dense waveguide array (e.g., spiral, AWG), see File:DesignRule VOC.pptx.
• Using L-Edit's DRC to make sure no VCs on waveguides

Mesa

• 14 um wide

QW

• 16 um wide

Thick p metal

• Same at N metal
• 4 um wide
• Keep 11 um separation between thick P and N metal.

N Metal

• 20 um wide

Implant

• 12 um wide
• Implant after anneal to ensure the quality

Via

• Min. 6 um opening
• Open up area that is uniform at bottom

Plating

• Use SPR series positive photoresist

Square/Circular TLM patterns design rules

• Distance between adjacent pads - 4 to 30 microns in 5 or more steps.

Smaller the distance, more accurate the estimate.

• Pad width/diameter must be atleast 2x the max distance between pads.

Eg. Say if you have 6 pads with 5,8,12,15,20 micron spacing, it is recommended that the pad be > (2x20) microns wide

• Rectangular/square pads will need to be etched on the outer sides for isolation. That is not the case with circular pads.

• With circular pads, it is difficult to lift-off small rings (<5 microns)

Keep radius between 30-60 microns.

• Also, it is good to have a set of PTLMs that will be exposed to implantation step. This would be a way to check if the

implantation was effective. Resistance between pads with implantation must be hundred or kilo ohms or larger.

First draft of document explaining these: File:DesignRules.xlsx

Processing Rules

Always put a dummy/witness sample in the chamber when depositing metals and dielectrics.

• Samples can later be used for determining thicknesses.
• These samples can also be used if a given layer has to be etched on the real sample, but etch is not well characterized.