CN107116308A - Waveguide micro/nano processing system and processing method - Google Patents

Abstract

The present invention provides a kind of low processing cost, the waveguide micro/nano processing system that precision is high, uniformity is good and processing method.Waveguide micro/nano processing system involved in the present invention, it is characterised in that including：There is provided laser beam in light source portion；Processing department, is focused the laser beam to and lithography process is carried out in substrate, and process is monitored in real time, is had：Zoom lens, three-dimensional appearance instrument, camera and temperature measurer；Multi-degree-of-freedom workbench, drives substrate to be moved on multiple free degree directions according to default waveguide patterns；Optical table, for laying multi-degree-of-freedom workbench, and completely cuts off extraneous vibration；Air blowing portion, is arranged on the side of multi-degree-of-freedom workbench, is blown against machining area；Suction unit, is arranged on the opposite side of multi-degree-of-freedom workbench, and blowing the gas come to air blowing portion absorbs；Control unit, connect and control light source portion, processing department, multi-degree-of-freedom workbench, optical table, the operation of air blowing portion and suction unit.

Description

Waveguide micro-nano processing system and processing method

technical field

The invention belongs to the field of micro-nano manufacturing and processing, and in particular relates to a waveguide micro-nano processing system and a corresponding processing method.

technical background

When the light wave is confined to propagate in the waveguide medium determined in the medium, the light wave channel formed by this medium is called an optical medium waveguide, or waveguide for short. At present, optical waveguides are mostly produced by chemical etching, ion etching and other methods. The above-mentioned methods have cumbersome processing steps, high requirements on the processing environment, and high processing costs.

Contents of the invention

The present invention is made to solve the above problems, and aims to provide a waveguide micro-nano processing system and processing method with low processing cost, high precision and good consistency.

In order to achieve the above object, the present invention adopts the following scheme:

<Option 1>

The present invention provides a waveguide micro-nano processing system, which is characterized in that it includes: a light source part, which provides a laser beam; a processing part, which is arranged on the optical path of the light source part, and is used to focus the laser beam on the substrate for photolithographic processing, and Real-time monitoring of the processing process, with: variable focus lens, 3D profiler, camera, and temperature measuring instrument; multi-degree-of-freedom workbench, carrying the substrate, and making the substrate face the processing part, driving the substrate in accordance with the preset waveguide pattern Move in multiple degrees of freedom directions; the optical platform is used to place the multi-degree-of-freedom workbench and isolate external vibration; the blowing part is set on one side of the multi-degree-of-freedom workbench to blow air towards the processing area; the suction The gas part is set on the other side of the multi-degree-of-freedom workbench, and absorbs the gas blown by the blower part; the control part is connected to and controls the light source part, processing part, multi-degree-of-freedom workbench, optical platform, part, and the operation of the suction part, wherein, the three-dimensional profiler monitors the surface topography of the lithographic groove on the substrate in real time during the processing, and feeds back the surface topography to the control part in real time, and the control part will receive the surface topography The topography is compared with the stored ideal surface topography, and the corresponding parameters of the light source unit and the focal length of the zoom lens are adjusted in real time to control the surface topography error within a certain range.

Furthermore, the waveguide micro-nano processing system provided by the present invention may also have the following features: the corresponding parameters of the light source part involved in the control part when adjusting the surface topography at least include: pulse frequency, laser power, and pulse duty cycle.

Furthermore, the waveguide micro-nano processing system provided by the present invention may also have the following features: the light source unit includes a laser, and the laser is any one of nanosecond, picosecond and femtosecond lasers.

Further, the waveguide micro-nano processing system provided by the present invention can also have the following features: the camera is a CCD industrial camera, which is used to monitor in real time whether there are foreign particles on the laser scanning path during processing, and when it is detected that there are foreign particles on the scanning path , the control unit adjusts the movement of the multi-degree-of-freedom table in real time, and adjusts the relevant parameters of the light source unit and the focal length of the zoom lens in real time, so as to focus the laser beam on the impurity particles for fixed-point ablation.

Furthermore, the waveguide micro-nano processing system provided by the present invention may also have the following features: the relevant parameters of the light source part that need to be adjusted for ablation of impurity particles include at least: laser spot size and laser power.

Further, the waveguide micro-nano processing system provided by the present invention may also have the following features: the temperature instrument monitors the surface temperature of the photolithographically processed part on the substrate in real time during the processing, and feeds back the surface temperature to the control part in real time, and the control part will The received surface temperature is compared with the set temperature threshold, and when the surface temperature is higher than the temperature threshold, the parameters of the light source part are adjusted to control the surface temperature of the photolithography process below the temperature threshold.

Furthermore, the waveguide micro-nano processing system provided by the present invention may also have the following features: the multi-degree-of-freedom workbench is a six-degree-of-freedom workbench.

Furthermore, the waveguide micro-nano processing system provided by the present invention may also have the following features: the surface of the six-degree-of-freedom workbench is provided with vacuum adsorption holes for adsorbing the substrate.

<Option 2>

In addition, the present invention also provides a waveguide micro-nano processing method, which uses the waveguide micro-nano processing system described in <Scheme 1> to perform waveguide micro-nano processing on the substrate, which is characterized in that it includes the following steps: photolithography processing step: The light source part provides the laser beam, and the laser beam is focused on the substrate through the variable focus lens for photolithography processing; blowing and dust removal steps: the blowing part blows air against one side of the processing area, while the suction part sucks from the other side gas, so as to collect the fine dust generated during the processing; path monitoring step: the camera monitors in real time whether there are impurity particles on the laser scanning path. , and adjust the relevant parameters of the light source part and the focal length of the variable focus lens in real time, so as to focus the laser beam on the impurity particles for fixed-point ablation; the three-dimensional shape monitoring step: the three-dimensional shape instrument monitors the surface of the photoetching groove on the substrate in real time The control part compares the surface topography with the stored ideal topography, adjusts the corresponding parameters of the light source part and the focal length of the zoom lens in real time, and controls the surface topography error within a certain range; the processing temperature monitoring step : The thermometer monitors the surface temperature of the photolithographically processed part on the substrate in real time, and the control part compares the surface temperature with the set temperature threshold, and adjusts the parameters of the light source part when the surface temperature is higher than the temperature threshold. Control the temperature of the surface being processed by photolithography below the temperature threshold.

Function and Effect of Invention

Using the waveguide micro-nano processing system and processing method provided by the present invention, since the multi-degree-of-freedom workbench is used to realize multi-degree-of-freedom movement, waveguides with arbitrary patterns can be processed, so that the processing system has strong manufacturing adaptability; further , through the air blowing part and the suction part to realize the convection of the gas in the processing part, it can suck away the dust to the maximum extent, and avoid the raw materials of the laser subtraction from being added by the laser. In this way, the processing environment is improved and the processing quality; further, since the three-dimensional topography instrument monitors the surface topography of the lithographic groove on the substrate in real time during the processing, and feeds back the surface topography to the control department in real time, the control department compares the received surface topography with the stored The ideal surface topography is compared, and the corresponding parameters of the light source part and the focal length of the zoom lens are adjusted in real time, so that the surface topography error is controlled within a certain range, thus greatly improving the processing accuracy. In summary, the waveguide device obtained by this processing system and processing method has good waveguide consistency and stable performance; the whole system is simple in equipment, directly etched by ultrafast laser, and the processing method has fewer steps, lower requirements on the processing environment, and is effective. Reduce the cost of waveguide production.

Description of drawings

Fig. 1 is a schematic structural diagram of a waveguide micro-nano processing system in an embodiment of the present invention.

detailed description

The waveguide micro-nano processing system and processing method involved in the present invention will be described in detail below with reference to the accompanying drawings.

<Example>

As shown in FIG. 1 , the waveguide micro-nano processing system 10 includes a light source unit 20 , a processing unit 30 , a multi-degree-of-freedom table 40 , an optical table 50 , an air blowing unit 60 , an air suction unit 70 , and a control unit 80 .

The light source section 20 includes a laser, which is any one of nanosecond, picosecond, and femtosecond lasers, for supplying a laser beam.

The processing part 30 is arranged on the optical path of the light source part 20, and is used to focus the laser beam on the substrate B for photolithography processing, and monitor the processing process in real time. The substrate B used for processing can be materials such as silicon dioxide, silicon, and ceramics.

The multi-degree-of-freedom table 40 is used to carry the substrate B, and make the substrate B face the processing part, and drive the substrate B to move in multiple degrees of freedom directions according to the preset waveguide pattern, so as to process the designed waveguide pattern. In this embodiment, the multi-degree-of-freedom workbench 40 is a six-degree-of-freedom workbench 40, which is used to drive the base B in directions of six degrees of freedom (ie, x-axis, y-axis, z-axis, pitch, rotation, and yaw) That is, the processing part 30 is in a static state, and the six-degree-of-freedom table 40 moves in a six-degree-of-freedom direction relative to the processing part 30 . The surface of the six-degree-of-freedom workbench 40 is provided with a vacuum suction hole 41 for absorbing the substrate B so that it is firmly fixed on the surface of the six-degree-of-freedom workbench 40 .

The optical platform 50 is used to place the six-degree-of-freedom worktable 40 and isolate external vibrations to improve machining accuracy.

The air blowing unit 60 is arranged on one side of the six-degree-of-freedom workbench 40 , and blows air against the photolithographic processing area on the substrate B to blow away the fine dust generated during the processing from the substrate B. In this embodiment, the gas blowing part 60 is a nitrogen gas flow.

The suction part 70 is set on the other side of the six-degree-of-freedom table 40, and sucks the gas blown by the blowing part 60, so as to collect the dust entrained in the gas, so as to ensure the cleanliness of the processing environment and improve the processing quality . In this way, the dust can be sucked away to the greatest extent, and the raw materials that are reduced by laser are prevented from being added by laser.

In addition, the power of the air blowing part 60 and the air suction part 70 can be adjusted in real time as required.

The control unit 80 is connected to the light source unit 20 , the processing unit 30 , the multi-degree-of-freedom table 40 , the optical table 50 , the air blowing unit 60 , and the air suction unit 70 , and controls their operations.

In this embodiment, the processing unit 30 includes a zoom lens, a three-dimensional topography instrument, a camera, and a temperature measuring instrument.

The variable focus lens is arranged on the optical path R of the light source part 20, and is used to focus the laser beam on the substrate B for photolithography processing, and monitor the processing process in real time, and its focal length can be adjusted in real time. In this embodiment, the optical path R may be in the form of an optical fiber or in the form of spatial light.

The three-dimensional topography instrument monitors the surface topography of the photolithographic groove on the substrate B in real time during the processing, and feeds back the surface topography to the control part 80 in real time, and the control part 80 compares the received surface topography with the stored ideal surface The topography is compared, and the corresponding parameters of the laser in the light source unit 20 and the focal length of the zoom lens are adjusted in real time to control the surface topography error within a certain range. In this embodiment, parameters such as pulse frequency, laser power, and pulse duty cycle in the laser can be adjusted to control the surface topography.

The camera is a CCD industrial camera, which is used to monitor in real time whether there are foreign particles on the laser scanning path during processing. Adjust the relevant parameters of the laser and the focal length of the variable focus lens to focus the laser beam on the impurity particles for fixed-point ablation. In this embodiment, parameters such as laser spot size and laser power in the laser can be adjusted in order to control the surface topography. In addition, a large amount of fine dust may be generated during the ablation process of impurity particles, so the power of the air blowing part 60 and the air suction part 70 can be increased in real time through the control part 80 as required.

The thermometer monitors the surface temperature of the photolithographically processed part on the substrate B in real time during the processing, and feeds back the surface temperature to the control unit 80 in real time, and the control unit 80 compares the received surface temperature with the set temperature threshold, And when the surface temperature is higher than the temperature threshold, the distance between the spot and the processing surface can be increased by reducing the laser power of the laser, or reducing the focal length of the zoom lens, or adjusting the six-degree-of-freedom table 40 to increase the distance between the spot and the processing surface. The surface temperature of the place to be photolithographically processed is controlled below the temperature threshold to prevent thermal deformation of the substrate B caused by temperature accumulation during laser processing.

The above is the specific structure of the waveguide micro-nano processing system 10. Taking the processing of polymer multi-mode optical waveguide arrays as an example, the method of using the waveguide micro-nano processing system 10 to perform waveguide micro-nano processing will be described. The specific steps of the method are as follows :

Step 1, prepare a silica substrate B of appropriate specifications, apply SU8 glue on the substrate B and use a glue homogenizer to spin the glue surface evenly to obtain a glue surface with a thickness of about 100 μm;

Step 2, putting the spin-coated silicon dioxide substrate B into an oven for heating, setting the heating temperature to 70°C and heating for 48 hours to obtain the lower cladding layer of the waveguide;

Step 3, fix the lower cladding of the waveguide processed in step 2 on the six-degree-of-freedom workbench 40 through the vacuum adsorption hole 41; use a picosecond laser as the light source, and write 16 lines along the X direction on the lower cladding. For the groove pattern, for the multimode optical waveguide array, the groove pitch is 256 μm, the groove width and groove depth are 65 μm; the specific process is as follows:

(1) Photolithography processing: import the designed writing pattern into the control part 80, and the six-degree-of-freedom table 40 moves in the direction of six degrees of freedom relative to the processing part 30 according to the imported pattern; at this time, start the light source part 20 and the processing part 30. The laser beam emitted by the laser in the light source part 20 is transmitted to the variable focus lens in the processing part 30 through the optical path R, and focused on the substrate 10 to engrave the designed pattern;

(2) Blowing, suction and dust removal: the blowing part 60 is aimed at the laser marking place and blows out the nitrogen gas flow from one side of the six-degree-of-freedom table 40, and the suction part 70 sucks in air from the other side to collect the micro particles generated during the processing. dust;

(3) Scanning path monitoring: The CCD industrial camera in the processing part 30 monitors in real time whether there are impurity particles on the laser scanning path during processing; when it detects that there are impurity particles on the scanning path, the control part 80 adjusts the six degrees of freedom in real time The movement of the worktable 40 adjusts the parameters of the laser in the light source part 20 and the focal length of the zoom lens in the processing part 30 in real time, and the laser beam is focused on the impurity particles for fixed-point ablation;

(4) Three-dimensional topography monitoring: the three-dimensional topography instrument in the processing part 30 monitors the surface topography of the engraved groove shape in real time during the processing, and feeds back the actually monitored surface topography to the control part 80 in real time, and the control part 80 comparing the surface topography with the ideal surface topography, adjusting the parameters of the laser in the light source part 20 and the focal length of the zoom lens in the processing part 30 in real time, and controlling the surface topography error within a certain range;

(5) Processing temperature monitoring: the thermometer in the processing part 30 monitors the surface temperature of the processing part in real time during processing, and feeds it back to the control part 80 in real time and compares it with the set processing temperature threshold. When the surface temperature of the processing place is higher than the temperature threshold at a certain moment, the parameters of the laser in the light source unit 20 are adjusted immediately through the control unit 80 to control the surface temperature of the processing place below the temperature threshold;

Step 4, mix the PDMS prepolymer and the corresponding curing agent according to a certain ratio, fill the mixture into the 16 grooves engraved, and scrape off the excess PDMS polymer with a scraper;

Step 5, place the lower cladding layer of the waveguide filled with PDMS polymer in step 4 in an oven, set the heating temperature to 70°C and the heating time for 24 hours, and complete the production of the core layer of the polymer multimode optical waveguide array;

Step 6: Coat the SU8 glue on the waveguide that has completed the core layer and use a glue leveler to spin the glue surface evenly to obtain a glue surface with a thickness of about 100 μm; put it into the oven, set the heating temperature to 70°C and the heating time to 48 hours, and the process is completed The cladding on the waveguide is fabricated to obtain the polymer multimode optical waveguide array.

In addition, for processing polymer single-mode optical waveguide arrays, it is only necessary to use a femtosecond laser as the light source in the above step 3 to write 16 groove patterns along the X direction on the lower cladding layer. For single-mode optical waveguide arrays , the groove pitch is 256 μm, the groove width and groove depth are 9 μm; other steps are as before, and will not be repeated here.

The above embodiments are merely illustrations for the technical solution of the present invention. The waveguide micro-nano processing system and processing method involved in the present invention are not limited to the contents described in the above embodiments, but are subject to the scope defined in the claims. Any modifications, supplements or equivalent replacements made by those skilled in the art of the present invention on the basis of the embodiments are within the protection scope of the claims of the present invention.

Claims (9)

1. a kind of waveguide micro/nano processing system, it is characterised in that including：

There is provided laser beam in light source portion；

In processing department, the light path for being arranged on the light source portion, lithography process is carried out in substrate for focusing the laser beam to, and it is right Process is monitored in real time, is had：Zoom lens, three-dimensional appearance instrument, camera and temperature measurer；

Multi-degree-of-freedom workbench, carries the substrate, and makes the substrate towards the processing department, according to default waveguide patterns The substrate is driven to be moved on multiple free degree directions；

Optical table, for laying the multi-degree-of-freedom workbench, and completely cuts off extraneous vibration；

Air blowing portion, is arranged on the side of the multi-degree-of-freedom workbench, is blown against machining area；

Suction unit, is arranged on the opposite side of the multi-degree-of-freedom workbench, and blowing the gas come to the air blowing portion absorbs；

Control unit, connects and controls the light source portion, the processing department, the multi-degree-of-freedom workbench, the optical table, institute The operation of air blowing portion and the suction unit is stated,

Wherein, the three-dimensional appearance instrument monitors the surface topography of the photoetching groove in the substrate in real time in process, and will The surface topography Real-time Feedback to control unit,

The control unit is contrasted the surface topography received and the desired surface topography of storage, and regulation is described in real time The focal length of the relevant parameter in light source portion and the Zoom lens, by surface topography control errors within the specific limits.

2. waveguide micro/nano processing system according to claim 1, it is characterised in that：

Wherein, the relevant parameter is comprised at least：Pulse frequency, laser power and pulse duty factor.

3. waveguide micro/nano processing system according to claim 1, it is characterised in that：

Wherein, the light source portion includes laser, and the laser is any one in nanosecond, psec and femto-second laser.

4. waveguide micro/nano processing system according to claim 1, it is characterised in that：

Wherein, the camera is CCD industrial cameras, for monitoring on laser beam scan path whether have miscellaneous in real time in process Matter particulate matter,

When monitoring to exist on scanning pattern the impurity particle thing, the control unit adjusts the multiple degrees of freedom work in real time The motion of platform, and the relevant parameter and the focal length of the Zoom lens in the light source portion of regulation in real time, thus by laser beam focus in Fixed point ablation is carried out at the impurity particle thing.

5. waveguide micro/nano processing system according to claim 4, it is characterised in that：

Wherein, the relevant parameter is comprised at least：Laser facula size and laser power.

6. waveguide micro/nano processing system according to claim 1, it is characterised in that：

Wherein, the thermometer monitors the surface temperature being photo-etched in the substrate at processing in real time in process, and will The surface temperature Real-time Feedback gives the control unit,

The control unit contrasts the surface temperature received and the temperature threshold of setting, and high in the surface temperature In the case of the temperature threshold, the parameter in the light source portion is adjusted, by the surface temperature control being photo-etched at processing in institute State below temperature threshold.

7. waveguide micro/nano processing system according to claim 1, it is characterised in that：

Wherein, the multi-degree-of-freedom workbench is six-freedom worktable.

8. waveguide micro/nano processing system according to claim 7, it is characterised in that：

Wherein, the surface of the six-freedom worktable is provided with vacuum absorption holes, for adsorbing the substrate.

9. a kind of waveguide micro-nano processing method, using the waveguide micro/nano processing system pair described in any one in claim 1 to 8 Substrate carries out waveguide wiener processing, it is characterised in that comprise the following steps：

Photolithographic steps：

Light source portion provides laser beam, and Zoom lens focus the laser beam to and lithography process is carried out in the substrate；

Blowing and sucking dust remover step：

Air blowing portion is blown against the side of machining area, while suction unit is from opposite side air-breathing, so as to collect process The micronic dust of middle generation；

Trace monitor step：

Whether camera is monitored in real time impurity particle thing on laser beam scan path, when monitoring there is the impurity on scanning pattern During particulate matter, control unit adjusts the motion of multi-degree-of-freedom workbench in real time, and adjust in real time the light source portion relevant parameter and The focal length of the Zoom lens, so that laser beam focus is carried out into fixed point ablation at the impurity particle thing；

Three-dimensional appearance monitoring step：

Three-dimensional appearance instrument monitors the surface topography of the photoetching groove in the substrate in real time, and by the control unit by the surface shape Looks and the desired surface topography of storage are contrasted, and the relevant parameter and the Zoom lens in the light source portion are adjusted in real time Focal length, by surface topography control errors within the specific limits；

Processing temperature monitoring step：

Thermometer monitors the surface temperature being photo-etched in the substrate at processing in real time, and by the control unit by the surface temperature Spend and contrasted with the temperature threshold set, and in the case where the surface temperature is higher than the temperature threshold, adjust the light The parameter in source portion, by the surface temperature control being photo-etched at processing below the temperature threshold.