US 11,988,904 B2
Slot waveguide for a phase shifter based on ferroelectric materials
Andreas Mai, Frankfurt (DE); Patrick Steglich, Frankfurt (DE); Christian Mai, Frankfurt (DE); Catherine Dubourdieu, Berlin (DE); Veeresh Deshpande, Berlin (DE); and Dong-Jik Kim, Berlin (DE)
Assigned to IHP GMBH—INNOVATIONS FOR HIGH PERFORMANCE MICROELECTRONICS / LEIBNIZ-INSTITUT FÜR INNOVATIVE MIKROELEKTRONIK, Frankfurt (DE)
Filed by IHP GmbH—Innovations for High Performance Microelectronics/ Leibniz-Institut fur Innovative Mikroel, Frankfurt (DE)
Filed on Dec. 21, 2021, as Appl. No. 17/557,345.
Claims priority of application No. 20216906 (EP), filed on Dec. 23, 2020.
Prior Publication US 2022/0197066 A1, Jun. 23, 2022
Int. Cl. G02F 1/025 (2006.01)
CPC G02F 1/025 (2013.01) 18 Claims
OG exemplary drawing
 
1. A slot waveguide (200) formed by a vertical material stack (202) comprising
a top layer (212) with a first refractive index,
a center layer (214) including a ferroelectric material and with a second refractive index, and
a Si1-xGex pseudosubstrate layer (216) with 0<x≤1 and with a third refractive index,
wherein the center layer (214) is grown on the Si1-xGex pseudosubstrate layer (216),
wherein the second refractive index is lower than the first refractive index and lower than the third refractive index such that field confinement inside the center layer (214) can be achieved, and
wherein the top layer (212) has an electrode region (310) with a doping concentration that is different to the remaining top layer (212).