CN102540334A - Manufacturing method for PLC (planar lightwave circuit) optical device - Google Patents

Abstract

The invention belongs to the technical field of planar lightwave circuit (PLC) splitters and specifically relates to a manufacturing method for optical waveguides, which comprises the following steps of: forming a layer of photo resists on a glass substrate; photo-etching to form patterns; forming an optical waveguide core layer with high refractive index in a groove formed among the photo resists; stripping the photo resists; and forming an upper film coating layer with low refractive index. The manufacturing method for the optical waveguides is simple in technological process, low in raw material and production equipment requirement, low in production cost and easy to realize the industrialization scale production.

Description

A kind of manufacturing approach of PLC optical device

Technical field

(Planar Lightwave Circuit, manufacturing approach PLC) is specifically related to a kind of method for manufacturing optical waveguide, belongs to PLC splitter technologies field to the present invention relates to a kind of planar light shunt.

Background technology

Current; The progressively expansion that FTTX (Optical Access Network) builds specifically will realize FTTC (Fiber To The Curb), FTTB (Fiber To The Building), FTTH (fiber-to-the-home front yard), FTTD (fiber to the desk), the integration of three networks multimedia transmission and PDS (comprehensive wiring system) schemes such as (voice network, data network, cable television networks).Build up Full Fibre Network, realize the continuing and reallocating of fiber optic network, also need the fiber-to-the-home purpose of the final completion of optical branching device in a large number except the various structure optical distribution cable of needs, leading in cable.

The PLC optical device is generally made on six kinds of materials, and they are: lithium niobate (LiNbO3), III-V family semiconducting compound, silicon dioxide (SiO ₂), SOI (Silicon-on-Insulator, silicon-on-insulator), polymkeric substance (Polymer) and glass.Wherein, the lithium niobate waveguide is to form waveguide through diffusion Ti ion on lithium columbate crystal, and waveguiding structure is a diffused.The InP waveguide is to claim the end and under-clad layer with InP, is sandwich layer with InGaAsP, is top covering with InP or InP/ air, and waveguiding structure is for burying ridged or ridged.SiO 2 waveguide is to claim the end with the silicon chip, with the SiO of difference doping ₂Material is sandwich layer and covering, and waveguiding structure is for burying rectangle.The SOI waveguide is on the SOI substrate, to make, and claims that the end, under-clad layer, sandwich layer and top covering material are respectively Si, SiO ₂, Si and air, waveguiding structure is a ridged.Polymer waveguide is to claim the end with the silicon chip, is sandwich layer with the Polymer material of different levels of doping, and waveguiding structure is for burying rectangle.Glass waveguide is to form waveguide through diffusion Ag ion on glass material, and waveguiding structure is a diffused.In the PLC of above-mentioned six kinds of materials optical device, silicon dioxide optical waveguide has good optical, electricity, mechanical property and thermal stability, is considered to the integrated technological approaches that practical prospect is arranged most of passive light.At present, the technology of manufacturing silicon dioxide optical waveguide is generally:

1) adopts flame hydrolysis (FHD) or chemical vapor deposition method (CVD), growth one deck SiO on silicon chip 101 ₂, wherein Doping Phosphorus, boron ion are as optical waveguide under-clad layer 102, shown in Fig. 1 a;

2) adopt FHD or CVD technology, regrowth one deck SiO on under-clad layer 102 ₂, as optical waveguide sandwich layer 103, doped germanium ion wherein, the refringence that acquisition needs, and the two-layer SiO of growth before making it through the annealing hardening process ₂Become evenly fine and close, shown in Fig. 1 b;

3) carry out photoetching, the optical waveguide figure of needs 104 is protected with photoresist, shown in Fig. 1 c;

4) adopt reactive ion etching (RIE) technology, non-optical waveguide zone is etched away, shown in Fig. 1 d;

5) remove photoresist, adopt FHD or CVD technology, on optical waveguide sandwich layer 103, cover one deck SiO again ₂, wherein Doping Phosphorus, boron ion as optical waveguide top covering 105, through the annealing hardening process, make top covering SiO then ₂Become evenly fine and close, shown in Fig. 1 e.

Aforesaid silicon dioxide optical waveguide technology is the main flow manufacturing technology of PLC optical device product at present, commonplace in the world employing.But problem is present in equipment and drops into height, high, the starting material requirement high (all adopting imported materials and items) of maintenance cost, and this technological manufacture difficulty is big.

Summary of the invention

In view of this, the objective of the invention is to propose a kind of manufacturing approach of silicon dioxide optical waveguide, can under lower cost input, realize the industrial large-scale production of silicon dioxide optical waveguide.

For reaching above-mentioned purpose of the present invention, the present invention proposes a kind of manufacturing approach of fiber waveguide device, specifically comprise:

A quartz glass substrate is provided;

The deposit photoresist;

Photoetching forms figure;

The deposit high refractive index layer;

Return and carve the said high refractive index layer of part, the said high refractive index layer removal on the photoresist is kept being deposited on the said high index of refraction layer material in the groove between the photoresist, to form high refractive index core;

Divest photoresist;

The deposit low refractive index film.

Wherein, in the manufacturing approach of above-mentioned fiber waveguide device, the thickness range of said photoresist is the 5-15 micron; The thickness range of described high refractive index core is the 2-20 micron, and its width range is the 2-30 micron.

Method for manufacturing optical waveguide technological process proposed by the invention is simple, and starting material and production equipment require low, have reduced production cost, are easy to realize industrial large-scale production.

Description of drawings

Fig. 1 a to Fig. 1 e is the manufacturing process flow diagram of the silicon dioxide optical waveguide of prior art.

Fig. 2 a is the synoptic diagram of an embodiment of silicon dioxide optical waveguide provided by the invention.

Fig. 2 b is that silicon dioxide optical waveguide shown in Fig. 2 a is along the sectional view of AB direction.

Fig. 3 a to Fig. 3 f is the process chart of an embodiment of manufacturing provided by the present invention silicon dioxide optical waveguide as shown in Figure 2.

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is done further detailed explanation, in the drawings, explanation is for ease amplified or has been dwindled the thickness of layer with the zone, shown in size do not represent physical size.Although the physical size that reflects device that these figure can not entirely accurate, their zones that still has been complete reflection and form the mutual alignment between the structure, particularly form between the structure up and down and neighbouring relations.Simultaneously in the following description, employed term substrate is appreciated that to be to comprise the just Semiconductor substrate in processes, possibly comprise other prepared thin layer above that.

Fig. 2 a is the synoptic diagram of an embodiment of optical waveguide provided by the present invention, and direction shown in the CD is the optical propagation direction in the silicon dioxide optical waveguide.Fig. 2 b is that optical waveguide shown in Fig. 2 a is along the sectional view of AB direction.Shown in Fig. 2 b, this optical waveguide comprises quartz substrate 301, waveguide core layer segment 302, the overlayer 303 of low-refraction and the lid 304 of quartz material as under-clad layer.

Silicon dioxide optical waveguide device proposed by the invention can be through a lot of method manufacturings, and below what narrated is the technological process of manufacturing provided by the present invention embodiment of silicon dioxide optical waveguide device shown in Fig. 2 b.

At first, the quartz substrate 201 of a twin polishing is provided, its thickness is preferably 1.25 millimeters.Follow deposit one deck negative photoresist 202 on quartz substrate 201, the thickness of photoresist 202 can be the 5-15 micron, and photoetching forms figure then, shown in Fig. 3 a.

Next, the method for employing spin coating forms the optical waveguide sandwich layer 203 of the high index of refraction of about 2 micron thick.Shown in Fig. 3 b, doping Ag ion is to improve its refractive index in spin-on material, and under the condition of 3000rpm, spin coating can obtain the high refractive index film of about 2-3 micron thick in 40 seconds.

Next, adopt the optical waveguide part of buffered hydrofluoric acid etch liquid (BHF) etching optical waveguide sandwich layer 203 formation devices, shown in Fig. 3 c.Divest photoresist 202 then, shown in Fig. 3 d.

Next, the method that continues the employing spin coating forms the overlayer 204 of the low-refraction of 2-20 micron thick, shown in Fig. 3 e.At last, piezoid is bonded on the overlayer 204 of low-refraction as lid 205, shown in Fig. 3 f, the thickness of piezoid 205 is preferably 1.25 millimeters.

As stated, under the situation that does not depart from spirit and scope of the invention, can also constitute many very embodiment of big difference that have.Should be appreciated that except like enclosed claim limited, the invention is not restricted at the instantiation described in the instructions.

Claims (3)

1. the manufacturing approach of a fiber waveguide device comprises:

A quartz glass substrate is provided;

The deposit photoresist;

Photoetching forms figure;

The deposit high refractive index layer;

Return and carve the said high refractive index layer of part, the said high refractive index layer removal on the photoresist is kept being deposited on the said high index of refraction layer material in the groove between the photoresist, to form high refractive index core;

Divest photoresist;

The deposit low refractive index film.

2. the manufacturing approach of fiber waveguide device according to claim 1 is characterized in that, the thickness range of said photoresist is the 5-15 micron.

3. the manufacturing approach of fiber waveguide device according to claim 1 is characterized in that, the thickness range of described high refractive index core is the 2-20 micron, and its width range is the 2-30 micron.

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