Source code for kqcircuits.squids.manhattan

# This code is part of KQCircuits
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from math import sqrt
from autologging import logged
from kqcircuits.pya_resolver import pya
from kqcircuits.util.parameters import Param, pdt
from kqcircuits.squids.squid import Squid
from kqcircuits.util.symmetric_polygons import polygon_with_vsym


[docs]@logged class Manhattan(Squid): """The PCell declaration for a Manhattan style SQUID. This SQUID has two distinct sub-types automatically selected by loop-area. """ finger_overshoot = Param(pdt.TypeDouble, "Length of fingers after the junction.", 1.0, unit="μm") include_base_metal_gap = Param(pdt.TypeBoolean, "Include base metal gap layer", True) shadow_margin = Param(pdt.TypeDouble, "Shadow layer margin near the the pads", 0.5, unit="μm") compact_geometry = Param(pdt.TypeBoolean, "Compact geometry for metal addition.", False) separate_junctions = Param(pdt.TypeBoolean, "Junctions to separate layer.", False) finger_overlap = Param(pdt.TypeDouble, "Length of fingers inside the pads.", 1.0, unit="μm")
[docs] def build(self): self.produce_manhattan_squid(top_pad_layer="SIS_junction")
[docs] def produce_manhattan_squid(self, top_pad_layer): # geometry constants big_loop_height = 10 loop_bottom_y = 1.5 self.metal_gap_top_y = 20 if self.compact_geometry else 26.5 self.width = 36 if self.compact_geometry else 38 # total width of junction layer self.height = 17 if self.compact_geometry else 20.2 # total height of junction layer bp_height = 5 # bottom pad height tp_width = 10 # top pad width brim_height = 1 # thickness of the "top-hat's" brim small_loop_height = 5.2 small_hat_width = 2 # width of the small hat shape, in case of small loop # corner rounding parameters rounding_params = { "rinner": 0.5, # inner corner rounding radius "router": 0.5, # outer corner rounding radius "n": 64, # number of point per rounded corner } # convenience variables delta_j = self.loop_area / big_loop_height # junction distance, a.k.a. loop width tp_height = self.height - loop_bottom_y - big_loop_height # top pad height bp_gap_x = -self.width / 2 + (self.width - delta_j) / 2 # bottom gap left edge x-coordinate bp_gap_x_min = -self.width / 2 + 7 # fixed at minimum size finger_margin = brim_height # make hats brim this much wider for good finger connection # adjust for small loop geometry small_loop = tp_width > -bp_gap_x * 2 if small_loop: bp_gap_x = bp_gap_x_min delta_j = self.loop_area / small_loop_height junction_shapes_top = [] junction_shapes_bottom = [] shadow_shapes = [] # create rounded bottom part bp_pts_left = [ pya.DPoint(-self.width / 2, -0.5), pya.DPoint(-self.width / 2, bp_height), pya.DPoint(bp_gap_x, bp_height), pya.DPoint(bp_gap_x, self.height - tp_height - big_loop_height) ] bp_shape = polygon_with_vsym(bp_pts_left) self._round_corners_and_append(bp_shape, junction_shapes_bottom, rounding_params) bp_shadow_pts_left = [ bp_pts_left[0] + pya.DPoint(-self.shadow_margin, -self.shadow_margin), bp_pts_left[1] + pya.DPoint(-self.shadow_margin, self.shadow_margin), bp_pts_left[2] + pya.DPoint(self.shadow_margin, self.shadow_margin), bp_pts_left[3] + pya.DPoint(self.shadow_margin, self.shadow_margin), ] bp_shadow_shape = polygon_with_vsym(bp_shadow_pts_left) self._round_corners_and_append(bp_shadow_shape, shadow_shapes, rounding_params) # create rounded top part tp_pts_left = [ pya.DPoint(-tp_width / 2, self.height), pya.DPoint(-tp_width / 2, self.height - tp_height), ] tp_shape = polygon_with_vsym(tp_pts_left) self._round_corners_and_append(tp_shape, junction_shapes_top, rounding_params) # add top pad to bottom shapes in case another layer is used for the upper part of the squid if top_pad_layer != "SIS_junction": self._round_corners_and_append(tp_shape, junction_shapes_bottom, rounding_params) tp_shadow_pts_left = [ tp_pts_left[0] + pya.DPoint(-self.shadow_margin, self.shadow_margin), tp_pts_left[1] + pya.DPoint(-self.shadow_margin, -self.shadow_margin), ] tp_shadow_shape = polygon_with_vsym(tp_shadow_pts_left) self._round_corners_and_append(tp_shadow_shape, shadow_shapes, rounding_params) # create rectangular junction-support structures and junctions if small_loop: small_hat = [ pya.DPoint(-small_hat_width / 2, self.height - tp_height), pya.DPoint(-small_hat_width / 2, small_loop_height + loop_bottom_y + brim_height), pya.DPoint(-delta_j / 2 - finger_margin, small_loop_height + loop_bottom_y + brim_height), pya.DPoint(-delta_j / 2 - finger_margin, small_loop_height + loop_bottom_y) ] junction_shapes_top.append(polygon_with_vsym(small_hat).to_itype(self.layout.dbu)) if top_pad_layer != "SIS_junction": junction_shapes_bottom.append(polygon_with_vsym(small_hat).to_itype(self.layout.dbu)) small_hat_shadow = [ small_hat[0] + pya.DPoint(-self.shadow_margin, -self.shadow_margin), small_hat[1] + pya.DPoint(-self.shadow_margin, self.shadow_margin), small_hat[2] + pya.DPoint(-self.shadow_margin, self.shadow_margin), small_hat[3] + pya.DPoint(-self.shadow_margin, -self.shadow_margin), ] shadow_shapes.append(polygon_with_vsym(small_hat_shadow).to_itype(self.layout.dbu)) small_hat[3].x += finger_margin self._make_junctions(small_hat[3], loop_bottom_y) else: tp_brim_left = [ pya.DPoint(-delta_j / 2 - finger_margin, self.height - tp_height + brim_height), pya.DPoint(-delta_j / 2 - finger_margin, self.height - tp_height) ] junction_shapes_top.append(polygon_with_vsym(tp_brim_left).to_itype(self.layout.dbu)) if top_pad_layer != "SIS_junction": junction_shapes_bottom.append(polygon_with_vsym(tp_brim_left).to_itype(self.layout.dbu)) tp_brim_shadow_pts = [ tp_brim_left[0] + pya.DPoint(-self.shadow_margin, self.shadow_margin), tp_brim_left[1] + pya.DPoint(-self.shadow_margin, -self.shadow_margin), ] shadow_shapes.append(polygon_with_vsym(tp_brim_shadow_pts).to_itype(self.layout.dbu)) tp_brim_left[1].x += finger_margin self._make_junctions(tp_brim_left[1], bp_height, finger_margin) self._add_shapes(junction_shapes_bottom, "SIS_junction") self._add_shapes(junction_shapes_top, top_pad_layer) self._add_shapes(shadow_shapes, "SIS_shadow") self._produce_ground_metal_shapes() self._produce_ground_grid_avoidance() self._add_refpoints()
def _make_junctions(self, top_corner, b_corner_y, finger_margin=0): """Create junction fingers and add them to some SIS layer. Choose 'SIS_junction' layer by default but 'SIS_junction_2' if ``separate_junctions`` is True. """ jx = top_corner.x - (top_corner.y - b_corner_y) / 2 jy = (top_corner.y + b_corner_y) / 2 dd = self.junction_width * sqrt(0.5) fo = self.finger_overshoot * sqrt(0.5) pl = self.finger_overlap * sqrt(0.5) # plus length to connect despite of rounding finger_points = [ pya.DPoint(top_corner.x + pl, top_corner.y + dd + pl), pya.DPoint(top_corner.x + dd + pl, top_corner.y + pl), pya.DPoint(jx - fo, jy - fo - dd), pya.DPoint(jx - fo - dd, jy - fo), ] finger = pya.DTrans(-jx, -jy) * pya.DPolygon(finger_points) junction_shapes = [(pya.DTrans(jx - finger_margin, jy) * finger).to_itype(self.layout.dbu), (pya.DTrans(0, False, jx - 2 * top_corner.x, jy) * finger).to_itype(self.layout.dbu), (pya.DTrans(3, False, jx - finger_margin, jy) * finger).to_itype(self.layout.dbu), (pya.DTrans(3, False, jx - 2 * top_corner.x, jy) * finger).to_itype(self.layout.dbu)] junction_region = pya.Region(junction_shapes).merged() layer_name = "SIS_junction_2" if self.separate_junctions else "SIS_junction" self.cell.shapes(self.get_layer(layer_name)).insert(junction_region) # place refpoints at the middle of the left and right junctions squa = sqrt(2) / 2 self.refpoints["l"] = pya.DPoint(jx - fo - finger_margin + self.finger_overshoot * squa, jy - fo + self.finger_overshoot * squa) self.refpoints["r"] = pya.DPoint(jx - fo - 2 * top_corner.x + self.finger_overshoot * squa, jy - fo + self.finger_overshoot * squa) def _add_shapes(self, shapes, layer): """Merge shapes into a region and add it to layer.""" region = pya.Region(shapes).merged() self.cell.shapes(self.get_layer(layer)).insert(region) def _add_refpoints(self): """Adds the "origin_squid" refpoint and port "common".""" self.refpoints["origin_squid"] = pya.DPoint(0, 0) self.add_port("common", pya.DPoint(0, self.metal_gap_top_y)) def _produce_ground_metal_shapes(self): """Produces hardcoded shapes in metal gap and metal addition layers.""" # metal additions bottom x0 = -12 if self.compact_geometry else -13 y0 = -1 bottom_pts = [ pya.DPoint(x0 - 3, y0 - 1), pya.DPoint(x0 - 3, y0 + 2), pya.DPoint(x0 - 5, y0 + 2), pya.DPoint(x0 - 5, y0 + 5), pya.DPoint(x0, y0 + 5), pya.DPoint(x0, y0 + 1) ] shape = polygon_with_vsym(bottom_pts) self.cell.shapes(self.get_layer("base_metal_addition")).insert(shape) # metal additions top y0 = 12 if self.compact_geometry else 14.5 top_pts = [ pya.DPoint(-2, y0 + 3), pya.DPoint(-2, y0 + 1), pya.DPoint(-1, y0 + 1), pya.DPoint(-1, y0), pya.DPoint(-4, y0), pya.DPoint(-4, self.metal_gap_top_y), ] shape = polygon_with_vsym(top_pts) self.cell.shapes(self.get_layer("base_metal_addition")).insert(shape) # metal gap if self.include_base_metal_gap: pts = bottom_pts[::-1] + [pya.DPoint(-20.5, -2), pya.DPoint(-20.5, self.metal_gap_top_y)] + top_pts[::-1] shape = polygon_with_vsym(pts) self.cell.shapes(self.get_layer("base_metal_gap_wo_grid")).insert(shape) def _produce_ground_grid_avoidance(self): """Add ground grid avoidance.""" w = self.cell.dbbox().width() h = self.cell.dbbox().height() protection = pya.DBox(-w / 2 - self.margin, -2 - self.margin, w / 2 + self.margin, h - 2 + self.margin) self.cell.shapes(self.get_layer("ground_grid_avoidance")).insert(protection) def _round_corners_and_append(self, polygon, polygon_list, rounding_params): """Rounds the corners of the polygon, converts it to integer coordinates, and adds it to the polygon list.""" polygon = polygon.round_corners(rounding_params["rinner"], rounding_params["router"], rounding_params["n"]) polygon_list.append(polygon.to_itype(self.layout.dbu))