CN110596798B

CN110596798B - Method for preparing microlens based on benzocyclobutene and silicon oxide balls

Info

Publication number: CN110596798B
Application number: CN201910915788.1A
Authority: CN
Inventors: 解意洋; 庞伟; 潘冠中; 徐晨; 王秋华
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2019-09-25
Filing date: 2019-09-25
Publication date: 2021-07-09
Anticipated expiration: 2039-09-25
Also published as: CN110596798A

Abstract

The invention discloses a method for preparing a micro-lens based on benzocyclobutene and silicon oxide spheres, which can be used for preparing micro-lenses with different spherical crown sizes and micro-lenses with different radians by using SiO2 and BCB as the preparation materials of the micro-lens. The micro-lens comprises a substrate, BCB and SiO2 microspheres, wherein the BCB mixed with the SiO2 microspheres is spin-coated on the substrate by a spin coater, and a micro-lens structure consisting of the BCB and the SiO2 microspheres is prepared on the substrate through heating curing and plasma etching (RIE). The SiO2 and BCB are used as the preparation materials of the micro lens, so that the micro lens with different spherical crown sizes and different radians can be prepared.

Description

Method for preparing microlens based on benzocyclobutene and silicon oxide balls

Technical Field

The invention belongs to the technical field of micro-nano processing, and particularly relates to a method for designing, processing and preparing a micro-lens.

Background

Microlenses have important applications in improving the beam quality of semiconductor light emitting devices (e.g., light emitting diodes, lasers, etc.), and have wide applications in optical communications, optical interconnects and optical switching, optical information processing, and micro-optical sensors. The conventional microlens preparation process has many disadvantages, such as rough lens surface, difficulty in forming uniform spherical lens, complicated processing steps, high processing cost, etc. Benzocyclobutene polymers (BCB) have a plurality of excellent properties (good film forming property, high film flatness, good retentivity, excellent mechanical property, high temperature resistance, small dielectric constant, small dielectric loss, low moisture absorption rate and the like), and are widely applied to the fields of high-tech microelectronic and electrical appliances, medical materials, aerospace, photoelectric devices, nonlinear optical materials and the like.

Disclosure of Invention

The invention aims to provide a simple and low-cost microlens preparation method based on an etching process, and the SiO2 and the BCB are used as the preparation materials of the microlens, so that the microlenses with different spherical crown sizes and different radians can be prepared.

As shown in fig. 1, one of the microlenses prepared based on the etching technique includes a substrate (1), BCB (2) and SiO2 microspheres (3), BCB (2) mixed with SiO2 microspheres (3) is spin-coated on the substrate (1) by a spin coater, and a microlens structure composed of BCB (2) and SiO2 microspheres (3) is prepared on the substrate (1) by heat curing and Reactive Ion Etching (RIE).

SiO₂The diameter of the microspheres (3) is 5 μm, 6 μm or 7 μm, respectively.

Therefore, the invention provides that the Reactive Ion Etching (RIE) technology is utilized to deeply and carefully research the preparation of microlenses with different spherical crown sizes and microlenses with the same spherical crown size by adopting silicon oxide pellets (the diameters are respectively 5 microns, 6 microns and 7 microns) and benzocyclobutene (BCB), the optimal parameters are determined, and the microlenses with different spherical crown diameters and good appearance are realized.

Drawings

FIG. 1: the invention adopts the side view of the whole structure of the microlens prepared by the etching process;

FIG. 2: a side view of the substrate;

FIG. 3: mixed with SiO₂A side view of BCB of microspheres spin coated on a substrate;

FIG. 4: etching a side view of the lens structure by Reactive Ion Etching (RIE);

in the figure: 1. substrate, 2, BCB, 3, SiO₂And (3) microspheres.

Detailed Description

The process for manufacturing the microlens of the present invention will be described with reference to fig. 2 to 4.

A microlens prepared based on etching technology comprises a substrate (1), BCB (2) and SiO₂Microspheres (3). Mixing SiO with a spin coater₂BCB (2) of the microspheres (3) is coated on the substrate (1) in a spin mode, the BCB is solidified by a hot plate, and then Reactive Ion Etching (RIE) is carried out on the substrate (1) to prepare the silicon-based composite material consisting of the BCB (2) and SiO₂A micro-lens structure formed by the microspheres (3).

A method for preparing a micro lens based on etching technology comprises the following steps:

step 1, cleaning a substrate (1) by using ultrasonic. The substrate (1) is placed in a beaker containing acetone, and then the beaker is placed in an ultrasonic machine for ultrasonic cleaning. After repeating twice, the acetone is changed into ethanol, and ultrasonic repeated cleaning is carried out again. Then the substrate (1) is washed by deionized water for 20 times or more; the substrate (1) after cleaning is obtained.

And 2, drying the cleaned substrate (1) by using a nitrogen gun, and then placing the substrate in an oven with the temperature of 100 ℃ for 5 minutes to ensure that the surface of the substrate (1) is dried.

Step 3, mixing SiO₂The microspheres (3) are uniformly dissolved in BCB (2). Weighing appropriate amount of SiO by electronic scale₂The microspheres (3) and the BCB (2) are dissolved together and then put into an ultrasonic cleaning machine for ultrasonic cleaning so as to ensure that the SiO2 microspheres (3) are uniformly distributed in the BCB (2).

Step 4, mixing the SiO by a spin coater₂BCB (2) of the microspheres (3) is spin-coated on the substrate (1), and the hot plate is provided with a corresponding temperature gradient to ensure that the BCB (2) is fully cured.

Step 5, etching the cured chip by Reactive Ion Etching (RIE), and controlling etching conditions and time to ensure SiO removal₂And 4, completely etching the BCB (2) outside the microsphere (3) area, thereby obtaining the structure of the micro-lens, and obtaining the micro-lens structure with different radians by continuously increasing the etching time.

The invention provides a method for preparing microlenses with different spherical crown sizes and microlenses with the same spherical crown size by adopting silicon oxide pellets (the diameters are respectively 5 mu m, 6 mu m and 7 mu m) and benzocyclobutene (BCB) and utilizing a Reactive Ion Etching (RIE) technology, which deeply and finely researches the preparation of the microlenses with different spherical crown sizes and the microlenses with the same spherical crown size, determines optimal parameters and realizes the microlenses with different spherical crown diameters and good appearance.

Claims

1. A microlens preparation method based on etching technology, the microlens for realizing the method comprises a substrate (1), BCB (2) and SiO₂Mixing the microspheres (3) with SiO by a spin coater₂BCB (2) of the microspheres (3) is spin-coated on the substrate (1), and the BCB (2) and SiO are prepared on the substrate (1) through heating curing and reactive ion etching₂A micro-lens structure composed of microspheres (3);

the method is characterized in that: the preparation process of the method is as follows,

step 1, cleaning a substrate (1) by using ultrasonic waves; the substrate (1) is placed in a beaker filled with acetone, and then the beaker is placed in an ultrasonic machine for ultrasonic cleaning; repeating the steps twice, changing the acetone into ethanol, and performing ultrasonic repeated cleaning again; then the substrate (1) is washed by deionized water for 20 times or more; obtaining the cleaned substrate (1);

step 2, drying the cleaned substrate (1) by using a nitrogen gun, and then placing the substrate in an oven with the temperature of 100 ℃ for 5 minutes to ensure that the surface of the substrate (1) is dried;

step 3, mixing SiO₂The microspheres (3) are uniformly dissolved in BCB (2); weighing appropriate amount of SiO by electronic scale₂Dissolving the microspheres (3) and the BCB (2) together, and then putting the mixture into an ultrasonic cleaning machine for ultrasonic cleaning to ensure that the SiO is ensured₂The microspheres (3) are uniformly distributed in the BCB (2);

step 4, mixing the SiO by a spin coater₂BCB (2) of the microspheres (3) is spin-coated on the substrate (1), and a corresponding temperature gradient is set on the hot plate to ensure that the BCB (2) is fully cured;

step 5, etching the solidified BCB (2) by using reactive ions, and controlling etching conditions and time to ensure SiO removal₂And 4, completely etching the BCB (2) outside the microsphere (3) area, thereby obtaining a micro-lens structure, and obtaining micro-lens structures with different radians by continuously increasing the etching time.

2. A method for manufacturing a microlens based on an etching technique according to claim 1, wherein: SiO2₂The diameter of the microspheres (3) is 5 μm, 6 μm or 7 μm, respectively.