WO2022104907A1

WO2022104907A1 - Micro-space three-dimensional morphology measurement apparatus

Info

Publication number: WO2022104907A1
Application number: PCT/CN2020/133055
Authority: WO
Inventors: 黄海阳; 赵瑛璇; 仇超; 盛振; 甘甫烷
Original assignee: 中国科学院上海微系统与信息技术研究所
Priority date: 2020-11-17
Filing date: 2020-12-01
Publication date: 2022-05-27
Also published as: CN112240754A

Abstract

A micro-space three-dimensional morphology measurement apparatus comprising a light source assembly and at least two detection assemblies, wherein the detection assemblies comprise substrates (8, 11), insulating layers (7, 12) are fixedly provided on the substrates (8, 11), a plurality of silicon wires (1, 2, 13) that are mutually parallel and have a same size and shape are arranged on the insulating layers (7, 12), and the distance between adjacent silicon wires (1, 2, 13) is the same, two ends of each silicon wire (1, 2, 13) both lead out wires (3, 4) and are connected to electrical potential measurement meters (5, 6), and the electrical potential measurement meters (5, 6) are connected to processors; the light source assembly performs line-by-line scanning on a surface of a measured sample (14) by means of laser light, and when laser light reflected by the measured sample (14) shines onto the detection assemblies, a near-field coupling effect occurs between the silicon wires (1, 2, 13) and the substrates (8, 11), and causes an amplitude of a resonator formed by the silicon wires (1, 2, 13) and the substrates (8, 11) to produce to be completely suppressed, and the processors calculate position information of a reflection point of the surface of the measured sample (14) according to continuous signals output by the electrical potential measurement meters (5, 6) connected to the silicon wires (1, 2, 13).

Description

A micro-space three-dimensional topography measurement device

technical field

The invention relates to the technical field of micro-nano photonic devices and micro-systems, in particular to a micro-space three-dimensional topography measuring device.

Background technique

The existing three-dimensional topography measurement devices are based on various probe measurement principles and based on the laser triangulation measurement principle. At the same time, various technologies also have certain limitations.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a small space three-dimensional topography measuring device, which has the advantages of small size, high precision, non-contact and the like.

The technical solution adopted by the present invention to solve the technical problem is to provide a micro-space three-dimensional topography measurement device, which includes a light source assembly and at least two sets of detection assemblies, the detection assemblies include a substrate, and a substrate is fixed on the substrate. The insulating layer is provided with several silicon wires that are parallel to each other and have the same shape and size, and the distances between adjacent silicon wires are equal. The potentiometer is connected to the processor; the light source assembly scans the surface of the sample to be tested line by line through the laser, and when the laser reflected by the sample to be tested is irradiated on the detection assembly, a near field occurs between the silicon wire and the substrate The resonator formed by the silicon wire and the substrate completely suppresses the amplitude of the coupling effect, and the processor calculates the position information of the reflection point on the surface of the tested sample according to the continuous signal output by the potentiometer connected to the silicon wire.

The distance between the adjacent silicon wires is one fifth of the wavelength of the laser light emitted by the light source assembly.

The thickness of the insulating layer is 15-20 nm.

The insulating layer is a transparent aluminum oxide isolation layer.

The substrate is a silver matrix in the shape of a rectangular parallelepiped.

The light source assembly includes a laser and a polygonal prismatic mirror, and the laser light emitted by the laser is reflected by the polygonal prismatic mirror and then irradiates the sample to be tested.

The laser can swing left and right through the first rotating shaft; the polygonal prism-shaped polygon mirror can rotate through the second rotating shaft.

beneficial effect

Compared with the prior art, the present invention has the following advantages and positive effects due to the adoption of the above technical solutions: the present invention has the advantages of small size, high precision, and non-contact.

Description of drawings

1 is a schematic structural diagram of an embodiment of the present invention;

2 is a schematic diagram of the principle of laser detection based on non-Hermitian coupling specific frequency in an embodiment of the present invention;

FIG. 3 is a schematic diagram of the principle of detecting the position of a point light source in an embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Embodiments of the present invention relate to a small space three-dimensional topography measurement device, as shown in FIG. 1 , including a light source assembly and at least two sets of detection assemblies.

Wherein, the detection component includes a substrate 11, and the substrate 11 is a silver matrix in the shape of a rectangular parallelepiped. An insulating layer 12 is fixed on the substrate 11 , and the insulating layer 12 is a transparent aluminum oxide isolation layer. The insulating layer 12 is provided with a plurality of silicon wires 13 that are parallel to each other and have the same shape and size, and the distance between adjacent silicon wires 13 is equal, and the distance is determined according to the wavelength of the laser used. Both ends of each silicon wire 13 lead out wires to be connected to a potentiometer, and the potentiometer is connected to the processor.

The light source assembly includes a laser 15 and a polygonal prismatic polygonal mirror 17 , and the laser light emitted by the laser 15 is reflected by the polygonal prismatic polygonal mirror 17 and then irradiates the sample to be tested 14 . The laser 15 swings left and right through the first rotating shaft 16 ; the polygonal prism-shaped polygon mirror 17 rotates through the second rotating shaft 18 .

The main parameters of the micro-space three-dimensional topography measuring device in this embodiment are as follows: the cross section of a single silicon wire 13 is 60*100nm, the center distance is 145nm, the material of the substrate 11 is metallic silver, and the wavelength emitted by the laser 15 is 727nm. Using conventional micro-nano processing technology, on the SOI wafer, first use electron beam lithography to etch silicon nanowires, then use ALD process to deposit an aluminum oxide isolation layer (15-20nm), and then use electron beam evaporation, Deposition of silver substrates. When the light source wavelength is 727nm and the incident angle is 50°, complete suppression can be achieved.

During operation, the laser light emitted by the above-mentioned light source assembly can scan the surface of the sample 14 to be tested line by line. When the laser reflected by the sample 14 to be tested irradiates the detection assembly, a near field occurs between the silicon wire 13 and the substrate 11 . The resonator formed by the silicon wire 13 and the substrate 11 can completely suppress the amplitude of the coupling effect, and the processor calculates the position information of the reflection point on the surface of the tested sample according to the continuous signal output by the potentiometer connected to the silicon wire.

The measurement principle of this embodiment is realized based on the non-Hermitian coupling specific frequency laser detection principle. In Fig. 2, 1 and 2 are parallel wires made of silicon material, L1 is a laser parallel beam that is vertically shot to wire 1 and wire 2 in space, and L2 is a laser parallel beam L1 is projected on the plane of wire 1 and wire 2. The obtained projection line, θ is the incident angle (the acute angle between the laser parallel beam L1 and the normal of the plane where the wire 1 and wire 2 are located), 7 is the transparent aluminum oxide isolation layer (insulating layer) with a certain thickness, 8 It is a silver backing. The wire 1 and the wire 2 are fixed on the transparent aluminum oxide isolation layer 7 , and the transparent aluminum oxide isolation layer 7 is fixedly connected with the silver substrate 8 . 3 and 4 are lead wires fixedly connected to both ends of lead 1 and

lead

2, 5 and 6 are potentiometers, and the potential difference at both ends of lead 1 and lead 2 can be measured through lead lead 3 and lead lead 4 respectively.

When the laser irradiates a single silicon wire, the silicon wire is illuminated, and a potential difference is generated across the silicon wire. In Figure 2, for the laser parallel beam L1 of a specific wavelength (eg: the wavelength range of the light source is 700-750nm), if the distance between the wire 1 and the wire 2 and the thickness of the aluminum oxide isolation layer 7 are appropriate (eg: the wire 1 and the wire 2) When the distance between them is one-fifth of the wavelength of light, and the thickness of the alumina isolation layer 7 is 15-20 nm), the two

parallel wires

1 and 2 and the silver substrate 8 in this case form a resonator together , under the irradiation of the laser parallel beam L1, a near-field coupling effect will occur between the wire 1, the wire 2 and the silver substrate 8. At this time, the brightness of the wire 1 and the wire 2 and the potential difference between the two ends will change. According to the coupled mode theory, the potential difference between the two ends of wire 1 and wire 2 is related to the incident angle θ. In particular, by carefully designing the parameters, it can be achieved that at a certain incident angle θ ₀ , the resonator amplitude is completely suppressed, that is, the resonator is close to the light source. The potential difference between the two ends of the wire 1 tends to zero, while the potential difference between the two ends of the wire 2 which is far from the light source does not change significantly. The laser incident angle θ ₀ at this position is called the coupling incident angle. In order to improve the detection sensitivity, it can be judged whether the light incident angle is the coupling incident angle θ ₀ according to the ratio of the potential difference between the two ends of the wire 1 and the wire 2: then when the light incident angle is the coupling incident angle θ ₀ , the two ends of the wire 1 and the wire 2 The potential difference ratio reaches an extreme value. According to this principle, the value of θ ₀ can be accurately measured.

Based on the above principle, a point light source position detection principle is shown in Figure 3. In the figure, 1a is a plurality of identical parallel wire groups made of silicon material, and 7a is a transparent aluminum oxide isolation layer with a certain thickness ( Insulation layer), 8a is a silver substrate, the size of the wire group 1a, the isolation layer 7a and the silver substrate 8a are appropriately set so that the adjacent wires in the wire group 1a all meet the conditions for the occurrence of the above-mentioned non-Hermitian coupling phenomenon; A scattered light source that emits or reflects light of a specific wavelength, with θ ₀ being the coupled incidence angle. According to the above-mentioned non-Hermitian coupling specific frequency laser detection principle, when the light emitted by point S is irradiated on the wire group 1a, the two wires A1 and A2 irradiated by the incident angle of the coupling incident angle θ ₀ appear dark, and the potential difference between their two ends close to zero.

The position of the light source can be obtained from the positions of the two dark wires in the wire group. Set the rectangular coordinate system oxy. In the rectangular coordinate system oxy, the seat of point A1 is marked as (x1, y1), the seat of point A2 is marked as (x2, y2), and the seat of light source S is marked as (x3, y3), Then the coordinates (x3, y3) of the light source S point can be obtained according to the coordinates of point A1 (x1, y1), the coordinates of point A2 (x2, y2) and θ ₀ :

It can be seen that, based on this principle, since the laser scans the surface of the sample to be measured 14 line by line, the measuring device of this embodiment can measure the three-dimensional topography of the surface of the sample to be measured 14 .

Claims

A micro-space three-dimensional topography measurement device, comprising a light source component and at least two sets of detection components, characterized in that the detection component includes a substrate, an insulating layer is fixed on the substrate, and an insulating layer is arranged on the insulating layer There are several silicon wires that are parallel to each other and have the same shape and size, and the distances between adjacent silicon wires are equal, and both ends of each silicon wire are led out of wires and connected to a potentiometer, and the potentiometer is connected to the processor; The light source assembly scans the surface of the sample to be tested line by line with laser light. When the laser reflected by the sample to be tested is irradiated on the detection assembly, a near-field coupling effect occurs between the silicon wire and the substrate, and the silicon wire and the substrate are connected. The resulting resonator produces a complete suppression of the amplitude, and the processor calculates the positional information of the reflective spot on the surface of the sample under test from the continuous signal output from the potentiometer connected to the silicon wire.
The device for measuring three-dimensional topography in tiny spaces according to claim 1, wherein the distance between the adjacent silicon wires is one-fifth of the wavelength of the laser light emitted by the light source assembly.
The device for measuring three-dimensional topography in tiny spaces according to claim 1, wherein the insulating layer has a thickness of 15-20 nm.
The device for measuring three-dimensional topography of tiny spaces according to claim 1, wherein the insulating layer is a transparent aluminum oxide insulating layer.
The device for measuring three-dimensional topography in tiny spaces according to claim 1, wherein the substrate is a silver matrix in the shape of a rectangular parallelepiped.
The device for measuring three-dimensional topography in a small space according to claim 1, wherein the light source component comprises a laser and a polygonal prismatic polygonal mirror, and the laser light emitted by the laser is reflected by the polygonal prismatic polygonal mirror. irradiate the sample to be tested.
The device for measuring three-dimensional topography in a small space according to claim 6, wherein the laser is swung left and right through a first rotation axis; the polygonal prism-shaped polygon mirror is rotated through a second rotation axis.