US 11,906,824 B2
Optical modulator using monocrystalline and polycrystalline silicon
Xunyuan Zhang, Mechanicsburg, PA (US); Vipulkumar K. Patel, Breinigsville, PA (US); Prakash B. Gothoskar, Allentown, PA (US); and Ming Gai Stanley Lo, Breinigsville, PA (US)
Assigned to Cisco Technology, Inc., San Jose, CA (US)
Filed by Cisco Technology, Inc., San Jose, CA (US)
Filed on Mar. 2, 2023, as Appl. No. 18/177,497.
Application 18/177,497 is a division of application No. 17/302,632, filed on May 7, 2021, granted, now 11,619,838.
Application 17/302,632 is a division of application No. 16/356,982, filed on Mar. 18, 2019, granted, now 11,036,069, issued on Jun. 15, 2021.
Prior Publication US 2023/0204987 A1, Jun. 29, 2023
Int. Cl. G02F 1/025 (2006.01)
CPC G02F 1/025 (2013.01) [G02F 2202/104 (2013.01); G02F 2202/105 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method, comprising:
patterning a base component to impart:
a lower waveguide that is separated from a substrate of the base component by a first layer of an insulator, the lower waveguide comprising:
a lower hub, made of monocrystalline silicon;
a lower ridge, made of monocrystalline silicon that extends in a first direction from the lower hub;
a first lower wing, made of monocrystalline silicon, that extends in a third direction, perpendicular to the first direction, from the lower hub;
a second lower wing, made of monocrystalline silicon, that extends in a fourth direction, opposite from the third direction, from the lower hub;
a first lower interface, made of monocrystalline silicon, located on a distal end of the first lower wing relative to the lower hub and extending upward in the first direction from the first lower wing; and
a second lower interface, made of monocrystalline silicon, located on a distal end of the second lower wing relative to the lower hub and extending in the first direction from the second lower wing;
an upper ridge for an upper waveguide that is located above the lower waveguide and is separated from the lower waveguide by a predefined height;
depositing a gate oxide layer on the lower waveguide;
depositing a second layer of the insulator on the gate oxide layer;
etching the second layer of the insulator to define a cavity of a predefined shape; and
forming polycrystalline silicon wings for the upper waveguide in the cavity.