# Basic DRC deck for the LiDAR SOI technology of this series
#
# Written to follow the SiEPIC EBeam PDK deck that ships with the PhotonForge DRC
# guide, so the structure and the idioms are ones a reader will meet again:
#   https://docs.flexcompute.com/projects/photonforge/en/latest/guides/SiEPIC_EBeam.drc
#
# The numbers are this technology's own: a single full etch of 220 nm silicon, a TiN
# heater, one routing metal, germanium detectors.
#
# Read about DRC scripts in the User Manual under "Design Rule Check (DRC)"
# http://klayout.de/doc/manual/drc_basic.html

source($gdsfile)

report("LiDAR DRC", $resultsfile)

# Layers, as the technology page numbered them
LayerSi = input(1, 0)
LayerSiPartial = input(2, 0)
LayerGe = input(7, 0)
LayerContact = input(10, 0)
LayerGeContact = input(11, 0)
LayerHeater = input(12, 0)
LayerVia = input(13, 0)
LayerM1 = input(14, 0)
LayerPadOpen = input(15, 0)

LayerFloorPlan = input(99, 0)

#################
# non-physical checks
#################

# Nothing may sit outside the chip area the floor plan marks out
LayerSi.outside(LayerFloorPlan).output("Boundary", "Si outside the floor plan")
LayerM1.outside(LayerFloorPlan).output("Boundary_M1", "M1 outside the floor plan")

#################
# physical checks
#################

tol = 1e-3  # users typically shoot for exactly the min features
            # for curves, this leads to lots of false errors.

# Silicon. The narrowest line drawn is the 180 nm edge coupler tip and the
# tightest gap is the 200 nm tap coupler. The antenna teeth are on the partial
# etch layer and have their own rules below.
LayerSi.width(0.15 - tol, angle_limit(80)).output("Si_width", "Si minimum feature size violation; min 150 nm")
LayerSi.space(0.15 - tol, angle_limit(80)).output("Si_space", "Si minimum space violation; min 150 nm")

# Partial-etch teeth: 100 to 200 nm wide, half a grating period apart
LayerSiPartial.width(0.1 - tol, angle_limit(80)).output("SiPartial_width", "Partial etch minimum feature size violation; min 100 nm")
LayerSiPartial.space(0.1 - tol, angle_limit(80)).output("SiPartial_space", "Partial etch minimum space violation; min 100 nm")

# Germanium is grown on a silicon seed and is drawn microns wide
LayerGe.width(1.0 - tol, angle_limit(80)).output("Ge_width", "Ge minimum feature size violation; min 1 um")
LayerGe.space(1.0 - tol, angle_limit(80)).output("Ge_space", "Ge minimum space violation; min 1 um")

# TiN heater, drawn 1 um wide over every phase shifter
LayerHeater.width(0.3 - tol, angle_limit(70)).output("Heater_width", "Heater minimum feature size violation; min 300 nm")
LayerHeater.space(0.3 - tol).output("Heater_space", "Heater minimum space violation; min 300 nm")

# Metal, drawn at 3 um for every trace and terminal
LayerM1.width(1.0 - tol, angle_limit(70)).output("M1_width", "M1 minimum feature size violation; min 1 um")
LayerM1.space(1.0 - tol).output("M1_space", "M1 minimum space violation; min 1 um")

# Contact plugs down to the silicon and to the germanium
LayerContact.width(0.5 - tol, angle_limit(70)).output("Contact_width", "Contact minimum feature size violation; min 500 nm")
LayerGeContact.width(0.5 - tol, angle_limit(70)).output("GeContact_width", "Ge contact minimum feature size violation; min 500 nm")

# Vias from the heater up to the metal, drawn 0.8 x 3 um on each heater end
LayerVia.width(0.5 - tol, angle_limit(70)).output("Via_width", "Via minimum feature size violation; min 500 nm")
LayerVia.space(1.0 - tol).output("Via_space", "Via minimum space violation; min 1 um")

# Pad openings in the passivation
LayerPadOpen.width(10.0 - tol).output("PadOpen_width", "Pad opening minimum feature size violation; min 10 um")
LayerPadOpen.space(10.0 - tol).output("PadOpen_space", "Pad opening minimum space violation; min 10 um")

#################
# cross-layer checks
#################

LayerM1.enclosing(LayerPadOpen, 2.5 - tol).output("M1_PadOpen_enclosure", "M1-PadOpen minimum enclosure violation; min 2.5 um")
LayerContact.not_inside(LayerSi).output("Contact_on_Si", "Contact must land on silicon, not on oxide")
LayerGeContact.not_inside(LayerGe).output("GeContact_on_Ge", "Ge contact must land on germanium")
LayerVia.not_inside(LayerHeater).output("Via_on_heater", "Via must land on the heater")
LayerVia.not_inside(LayerM1).output("Via_in_M1", "Via must be covered by M1")

# Metal half a micron above a heater is a heat sink and changes its efficiency, so the
# only metal allowed over a heater is the landing on its via
LayerM1.and(LayerHeater).not_inside(LayerVia.sized(1.5)).output("M1_over_heater", "M1 over a heater away from its via")