Silicon-based lithium niobate film electro-optic modulator array and integration method thereof

A method for integrating a silicon-based lithium niobate film electro-optic modulator array, comprising:

• (1) oxidizing a smooth silicon crystal substrate (2) by thermal oxidation to form a silicon dioxide film layer (3);
• (2) depositing polycrystalline silicon with a certain thickness on the silicon dioxide film layer (3) by chemical vapor deposition (CVD), and forming silicon waveguide layers (4) with a plurality of silicon-based lithium niobate film electro-optic modulators (1) arranged in an array by dry etching or wet etching, wherein the silicon waveguide layers (4) comprise optical splitters (41) and optical couplers (42) of all the electro-optic modulators arranged in the array, an input terminal of each of the optical splitters (41) is an incident light port, and an output terminal of each of the optical couplers (42) is a modulated light output port;
• and optical output ports and optical input ports between the modulators are interconnected to form a cascading, parallel or hybrid structure;
• (3) for each electro-optic modulator (1) in an array, performing ion implantation on two sides of the silicon waveguide (4) where a direct-current voltage is to be applied, wherein phosphorus ions are implanted on one side while boron ions are implanted on the other side to form a PN junction across the silicon waveguide;
• (4) forming a metal layer on the silicon waveguide layers (4) by chemical vapor deposition, and removing excess metal by a dry etching process to form metal connection lines only above the PN junctions and form metal lines connected to the outside such that a direct-current bias electrode layer (7) and direct-current bias input ports are made;
• (5) etching a wafer-level lithium niobate wafer by dry etching or wet etching to form periodic ridge structures to fabricate a lithium niobate film layer (6), and covering all the N silicon waveguide layers (4) arranged in the array with the lithium niobate film layer (6);
• (6) aligning the ridge structures on the lithium niobate film layer (6) with the optical couplers (42) arranged in the array in the silicon waveguide layers (4), and bonding the lithium niobate film layer (6) and the silicon waveguide layers (4) by using an adhesive (5);
• and
• (7) forming a metal layer on the lithium niobate film layer (6) by chemical vapor deposition, and then removing excess metal by dry etching or wet etching while only leaving, for each electro-optic modulator, radio-frequency metal electrodes in regions where a radio-frequency signal is to be applied and radio-frequency electrode metal connection lines connected to the outside to form a radio-frequency electrode layer (8) and radio-frequency signal input ports;
• thus obtaining the array integrating N electro-optic modulators having 2*N optical splitters (41) arranged in the array, 2*N optical couplers (42) arranged in the array, N direct-current voltage input ports and N radio-frequency input ports.