CN106910665A - A kind of full-automatic SEM and its detection method - Google Patents

Abstract

This article provides a fully automated scanning electron microscope and its detection method. The scanning electron microscope includes: an optical navigation system composed of a first optical microscope and a translation stage, and a scanning electron microscope composed of an electron source and an electron optical lens barrel. Microscope device, the optical navigation system also includes: a first chamber located below the first optical microscope and connected to the translation stage, accommodating the sample to be tested for optical detection; the scanning electron microscope device also includes: The second chamber below the electron optical lens barrel that accommodates the sample to be tested for scanning electron microscope detection; the first chamber and the second chamber are horizontally connected or isolated by a vacuum valve; in the first chamber An automatic transfer device capable of moving the sample to be tested from the first chamber to the second chamber through the vacuum valve is provided. The application is simple to operate, and can achieve the purpose of shortening the sample detection time and improving detection efficiency and accuracy.

Description

A fully automated scanning electron microscope and its detection method

technical field

The invention relates to the technical field of scanning electron microscopes, in particular to a fully automatic scanning electron microscope and a detection method thereof.

Background technique

The traditional optical system has the characteristics of simple operation and convenience for observing objects, and the preparation of samples is simple, and does not require strict observation conditions such as high vacuum, so it is often used for rapid microscopic observation of objects. Due to the low resolution of the traditional optical system, it is limited in the high-resolution detection of objects. In observing microscopic objects, scanning electron microscopes (Scanning Electron Microscope, SEM) are widely used due to their high resolution and large depth of field.

Since the traditional scanning electron microscope needs a high magnification when observing the fine information of the object, the field of view is small, and it is difficult to locate the position to be measured. Usually, it is necessary to locate the position of the sample to be tested with the help of images obtained under the condition of a large field of view. However, when the scanning electron microscope detects in a large field of view, the distortion generated at the edge of the field of view is very large, which cannot truly reflect the surface morphology of the sample. Therefore, when the scanning electron microscope image obtained under the large field of view is used to locate the sample to be tested , often inaccurate positioning. The highest resolution of the optical system is 200nm, and the distortion of the optical system is much smaller than the distortion produced by the scanning electron microscope when observing a large field of view. Therefore, the combination of the optical system and the scanning electron microscope is used to detect objects: first use the optical system to find The target position, and then use scanning electron microscopy for higher-resolution observations, this method is an effective way to solve this problem.

Scanning electron microscope systems combined with optical systems are large, complex instruments. During use, the sample chamber of the scanning electron microscope needs to be evacuated to a certain vacuum value, which takes a long time; and for the user, manually transporting the sample from the optical system detection area to the scanning electron microscope detection In the area, it is difficult for even professional technical operators to ensure accurate movement and positioning of the sample. In order to ensure high work efficiency and precision, the traditional manual operation is far from meeting the demand, which greatly limits the systematic use of the scanning electron microscope combined with the optical system.

Therefore, there is a need for a system that can fully automate the detection from the optical system to the scanning electron microscope, so as to make up for the inconvenience caused by manual operation, shorten the detection time, simplify the operation, and improve the detection efficiency and accuracy.

Contents of the invention

In view of this, the embodiment of the present invention expects to provide a fully automated scanning electron microscope and its detection method, which is easy to operate, can achieve the purpose of shortening the sample detection time, and improving detection efficiency and accuracy.

In order to achieve the above object, the technical solution of the embodiment of the present invention is achieved in this way:

The invention provides a fully automated scanning electron microscope, comprising an optical navigation system composed of a first optical microscope and a translation stage, and a scanning electron microscope device composed of an electron source and an electron optical lens barrel,

The optical navigation system also includes: a first chamber located below the first optical microscope and connected to the translation stage, accommodating the sample to be tested for optical detection;

The scanning electron microscope device also includes: a second chamber located below the electron optical lens barrel, accommodating the sample to be tested for scanning electron microscope detection;

The first chamber and the second chamber are horizontally connected or isolated by a vacuum valve; the first chamber is provided with a device capable of moving the sample to be tested from the first chamber to the second chamber through the vacuum valve. Automatic transfer of chambers.

Wherein, the top of the first chamber is provided with a first observation window that allows the illumination beam and imaging beam of the first optical microscope to pass through; Sample door.

Wherein, the second chamber is provided with a sample table that carries and controls the horizontal and vertical movement of the sample to be tested; the sample table is provided with an automatic fixing device for fixing the sample to be tested.

In the embodiment of the present invention, the second chamber further includes: an automatic focus tracking system arranged above the sample stage to measure the height of the surface of the sample to be tested in real time.

In the embodiment of the present invention, the automatic transfer device is arranged on the sample change door of the first chamber.

Wherein, the automatic conveying device includes: a first telescopic conveying arm fixed on the sample changing door, and a first sample holder connected to the other end of the first telescopic conveying arm carrying the sample to be tested.

In the embodiment of the present invention, the automatic conveying device is arranged in the first chamber through a vertical rotating shaft.

Wherein, the automatic transfer device includes: a second telescopic transfer arm with one end fixed to the rotating shaft and rotating in the horizontal direction around the rotating shaft; Two sample holders.

In the above solution, a second optical microscope is also provided above the second chamber, and a second observation window that allows light beam transmission is provided at a position opposite to the second optical microscope on the top of the second chamber in the vertical direction. .

The embodiment of the present invention also provides a fully automated scanning electron microscope detection method, the method comprising:

The optical navigation system is used for optical detection of the sample to be tested, and the overall navigation map of the surface of the sample to be tested is obtained;

The sample to be tested in the first chamber is transferred to the second chamber through the vacuum valve through the automatic transfer device;

Based on the overall navigation map of the surface of the sample to be measured, locate the designated position of the sample to be measured, and use a scanning electron microscope device to perform scanning electron microscope detection on the designated position of the sample to be measured, to obtain the designated position of the sample to be measured information at

Wherein, when said sample to be tested is optically detected, the method also includes:

The first and second chambers are evacuated to a vacuum state.

Wherein, before said sample to be tested is optically detected, the method also includes:

The sample to be tested is placed in the first chamber through the sample changing door of the first chamber to perform the optical detection.

Wherein, said moving the sample to be tested in the first chamber to the second chamber through the vacuum valve through the automatic conveying device includes:

The automatic transfer device moves the sample to be tested to the second chamber through the opened vacuum valve through translation, or through translation and rotation; the sample stage in the second chamber moves to the bottom of the sample holder of the automatic transfer device, The sample to be tested is lifted up, and the sample to be tested is fixed by an automatic fixing device on the sample stage.

In the embodiment of the present invention, when performing scanning electron microscope detection on the specified position of the sample to be tested, the method further includes:

The height of the surface of the sample to be tested is measured in real time by the automatic focus tracking system, and the height of the sample stage in the second chamber is adjusted based on the measurement result, so that the electron beam is focused on the surface of the sample to be tested in real time.

In the above scheme, after the sample to be tested is moved to the second chamber, and before scanning electron microscope detection, the method further includes:

The second optical microscope above the second chamber is used to check whether the position of the sample to be tested on the sample stage is correct through the second observation window on the top of the second chamber.

In the fully automated scanning electron microscope and its detection method provided by the embodiments of the present invention, the optical navigation system composed of the first optical microscope and the translation stage performs optical detection on the sample to obtain the sample surface navigation map; the automatic scanning electron microscope in the first chamber The conveying device and the automatic fixing device on the sample stage quickly and accurately complete the sample delivery process; based on the overall navigation map of the surface of the sample to be tested, the specified position of the sample to be tested is precisely positioned, and the height of the sample surface is measured by the automatic focus tracking system. The height of the sample stage is adjusted to ensure the real-time focusing of the electron beam of the scanning electron microscope on the sample, so that the scanning electron microscope detects the specified position of the sample to be measured, and obtains the information at the specified position of the sample to be measured. The entire moving process does not require manual operation, which improves detection efficiency and accuracy.

In addition, the first chamber and the second chamber are connected through a vacuum valve, and by properly controlling the opening and closing of the vacuum valve, the vacuum state of the second chamber can be guaranteed as much as possible, and the impact on the first chamber can be shortened. and the time spent in vacuuming the second chamber, thereby shortening the time spent in the entire detection process.

Description of drawings

Fig. 1 is a structural schematic diagram 1 of a fully automated scanning electron microscope according to an embodiment of the present invention;

Fig. 2 is the structural schematic diagram II of the fully automated scanning electron microscope described in the embodiment of the present invention;

Fig. 3 is a structural schematic diagram 1 of the automatic conveying device according to the embodiment of the present invention;

Fig. 4 is a schematic diagram II of the structure of the automatic conveying device according to the embodiment of the present invention;

Fig. 5 is a flow chart of the detection method of the fully automated scanning electron microscope according to the embodiment of the present invention.

detailed description

The present invention will be described below in conjunction with the accompanying drawings and embodiments.

Parts irrelevant to the present invention are not described again, and the same reference numerals designate the same elements throughout the specification.

The embodiment of the present invention provides a fully automated scanning electron microscope, as shown in FIG. 103 constitutes a scanning electron microscope device 100, wherein,

The optical navigation system 120 also includes: a first chamber 109 located below the first optical microscope 108 and connected to the translation stage 113 to accommodate the sample 116 to be tested for optical detection; the scanning electron microscope device 100 It also includes: a second chamber 106 located below the electron optical column 103 to accommodate the sample 116 to be tested for scanning electron microscope detection; a vacuum valve 107 is passed between the first chamber 109 and the second chamber 106 Horizontal communication or isolation; the first chamber 109 is provided with an automatic transfer device 115 capable of transferring the sample to be tested from the first chamber 109 to the second chamber 106 through the vacuum valve 107 .

As shown in Figure 1, the top of described first chamber 109 is provided with the first observation window 114 that allows the illuminating light beam of described first optical microscope 108 and imaging light beam to pass through; There is a sample change door 110 that allows the sample to be tested 116 to enter and exit.

Wherein, the first optical microscope 108 uses the first observation window 114 as a beam propagation channel to image a certain position of the sample to be measured 116; the translation stage 113 can adjust the first An optical microscope 108, so that the first optical microscope 108 is focused on the surface of the sample 116 to be tested; the first optical microscope 108 can also be controlled to move two-dimensionally in the plane formed by the X axis and the Y axis, so as to obtain An image of each position on the sample to be tested 116 .

The scanning electron microscope device 100 is used to detect the specified position information on the surface of the sample 116 to be tested. The electron source 101 is used to generate an electron beam 102, and the electron beam 102 is irradiated to the sample to be tested 116 placed on the sample stage 111 in the second chamber 106 to realize the detection of the sample to be tested 116 ;

The electron optical lens barrel 103 mainly includes: a deflection device 104, which is used to deflect the electron beam 102; a focusing device 105, which is used to focus the electron beam 102, and its function can usually be realized by an electromagnetic lens;

The second chamber 106 mainly includes: a sample stage 111 that carries and controls the movement of the sample to be tested in the horizontal and vertical directions, that is, the sample stage 111 can be moved up and down along the Z axis, and can also be moved between the X axis and the Y axis. Two-dimensional movement in the composed plane; the sample table 111 is provided with an automatic fixing device 112 for fixing the sample to be tested, for automatically fixing the sample to be tested 116 delivered by the automatic transfer device 115 to the sample table 111 On, it can choose electrostatic chuck;

As shown in Figure 1, the second chamber 106 also includes: an automatic focus tracking system 118 arranged above the sample stage 111, which is used to measure the surface height of the sample 116 to be tested in real time, and the sample can be adjusted based on the measurement result. The height of the table 111 makes the electron beam focus on the surface of the sample to be tested in real time, and the electron beam focal point is the position shown in 117 in Fig. 1; It is used to isolate the first chamber 109 and the second chamber 106 to maintain their respective vacuum states.

The embodiment of the present invention provides a structure of an automatic transfer device. As shown in FIG. into the second chamber 106. It mainly includes: the first telescopic transfer arm 318 and the first sample holder 319; wherein,

One end of the first telescopic transfer arm 318 is fixed on the sample changing door 110, and the translation of the sample 116 to be tested is realized through the action of stretching and shrinking;

The first sample holder 319 is a chuck connected to the other end of the first telescopic delivery arm 318 for carrying the sample 116 to be tested.

The embodiment of the present invention also provides another automatic transfer device. As shown in FIG. 4, the automatic transfer device 115 passes through a vertical rotating shaft (in FIG. A vertical structure at the bottom of a chamber) is arranged in the first chamber 109 for automatically transferring the sample to be tested 116 into the second chamber 106, mainly including: a second telescopic transfer arm 418 and a second sample holder 419; wherein,

The second telescopic transmission arm 418 is located in the first chamber, and can realize rotation and expansion and contraction. The translation of the sample 116 to be tested can be realized through expansion and contraction. Rotate to transfer the sample 116 to be tested from the first chamber 109 to the second chamber 106;

The second sample holder 419 is a chuck connected to the other end of the second telescopic delivery arm 418 for carrying the sample 116 to be tested.

On the basis of the above embodiments, the embodiment of the present invention also provides another fully automated scanning electron microscope, as shown in Figure 2, on the basis of the structure shown in Figure 1, another optical microscope is added, namely: The second optical microscope 200 and the second observation window 201 .

The second optical microscope 200, located above the second chamber 106, is used to check whether the position of the sample to be tested 116 on the sample stage 111 is accurate;

The second observation window 201 is located at the top of the second chamber 106 at a position opposite to the second optical microscope 200 in the vertical direction, serving as a beam transmission channel.

The detection method of the above-mentioned fully automated scanning electron microscope is briefly introduced below, as shown in Figure 5, the method includes:

Step 501: Using the optical navigation system 120 to perform optical detection on the sample to be tested to obtain an overall navigation map of the surface of the sample to be tested;

Specifically, the optical navigation system 120 uses the first observation window 114 on the top of the first chamber 109 as a beam propagation channel to image a certain position of the sample 116 to be tested by the first optical microscope 108; the translation stage 113 carries the first The optical microscope 108 moves two-dimensionally in the plane formed by the X-axis and the Y-axis above the first observation window 114, thereby acquiring an image of each position on the surface of the sample to be measured; The images are made into a holistic navigation map of the sample surface.

Step 502: The automatic transfer device 115 transfers the sample to be tested in the first chamber 109 to the second chamber 106 through the vacuum valve 107; including:

The automatic transport device 115 transmits the sample to be tested to the second chamber 106 through the opened vacuum valve 107 by translation, or by translation and rotation; the sample stage 111 in the second chamber 106 moves to the automatic transport Under the sample holder of the device 115 , the sample to be tested is lifted up, and the sample to be tested is fixed by the automatic fixing device 112 on the sample stage 111 .

Specifically, this step mainly requires the following four operations: First, the first sample holder 319 carrying the sample to be tested is moved by the first telescopic transfer arm 318 or the second telescopic transfer arm 418 in the automatic transfer device 115 Or the second sample holder 419 is transferred to the second chamber 106; then, the sample stage 111 moves horizontally to the bottom of the first sample holder 319 or the second sample holder 419, the sample stage 111 is raised, and the first sample holder 419 is raised. The sample to be measured on the first sample holder 319 or the second sample holder 419 is lifted; secondly, the sample to be tested is fixed on the sample table 111 by the automatic fixing device 112 on the sample table 111; Finally, withdraw the first sample holder 319 or the second sample holder 419 to the first chamber 109 and close the vacuum valve 107 .

Step 503: Based on the overall navigation map of the surface of the sample to be tested, locate the specified position of the sample to be tested, and use the scanning electron microscope device 100 to perform scanning electron microscope detection on the specified position of the sample to be tested, and obtain the sample to be tested. Information at the specified location described above.

Here, the scanning electron microscope detection includes the following operations: using the overall navigation map obtained by the optical navigation system 120 to identify and locate the designated location of the sample to be tested; the height of the surface of the sample to be measured, adjust the height of the sample stage 111 in the second chamber based on the measurement result, so that the electron beam is focused on the surface of the sample to be measured in real time; after that, use the deflected and focused electron beam 102 to detect the sample to be measured , to obtain a high-magnification image of a specified position on the surface of the sample to be tested.

In order to shorten the detection time of the fully automated scanning electron microscope, when the sample to be tested is optically detected, the method also includes:

The first and second chambers are evacuated to a vacuum state.

Wherein, before said sample to be tested is optically detected, the method also includes:

The sample to be tested is placed in the first chamber through the sample changing door 110 of the first chamber to perform the optical detection. It should be noted that when the sample change door 110 is opened, the vacuum valve 107 is in a closed state, so as to ensure the vacuum state of the second chamber as much as possible.

In the above scheme, after the sample to be tested is moved to the second chamber, and before scanning electron microscope detection, the method further includes:

Using the second optical microscope 200 above the second chamber, check whether the position of the sample to be tested on the sample stage is correct through the second observation window 201 on the top of the second chamber.

The embodiment of the present invention quickly and accurately completes the sample delivery process through the automatic transmission device and the automatic fixing device, and moves the sample to be tested that has completed the optical detection to the scanning electron microscope device for subsequent scanning electron microscope detection. Manual operation is required, which improves detection efficiency and accuracy.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (15)

1. A fully automated scanning electron microscope, comprising an optical navigation system made of the first optical microscope and a translation platform, and a scanning electron microscope device made of an electron source and an electron optical lens barrel, characterized in that, The optical navigation system also includes: a first chamber located below the first optical microscope and connected to the translation stage, accommodating the sample to be tested for optical detection; The scanning electron microscope device also includes: a second chamber located below the electron optical lens barrel, accommodating the sample to be tested for scanning electron microscope detection; The first chamber and the second chamber are horizontally connected or isolated by a vacuum valve; the first chamber is provided with a device capable of moving the sample to be tested from the first chamber to the second chamber through the vacuum valve. Automatic transfer of chambers. 2. The scanning electron microscope according to claim 1, wherein the top of the first chamber is provided with a first observation window that allows the illumination light beam and imaging light beam of the first optical microscope to pass through; A side wall of a chamber is provided with a sample changing door allowing the sample to be tested to enter and exit. 3. scanning electron microscope according to claim 1, is characterized in that, is provided with in the described second chamber the sample table that carries and controls the sample to be measured to move in horizontal, vertical direction; Described sample table is provided with fixed The automatic fixing device of the sample to be tested. 4 . The scanning electron microscope according to claim 3 , wherein the second chamber further comprises: an automatic focus tracking system arranged above the sample stage to measure the surface height of the sample to be measured in real time. 5 . 5 . The scanning electron microscope according to claim 2 , wherein the automatic transfer device is arranged on a sample change door of the first chamber. 6 . 6. The scanning electron microscope according to claim 5, wherein the automatic conveying device comprises: a first telescopic conveying arm fixed on the sample changing door, and a telescopic conveying arm connected to the first telescopic conveying arm. The first sample holder at the other end of the arm carries the sample to be tested. 7 . The scanning electron microscope according to claim 1 , wherein the automatic transport device is disposed in the first chamber through a vertical rotating shaft. 7 . 8. The scanning electron microscope according to claim 7, wherein the automatic transport device comprises: a second telescopic transport arm that is fixed at one end to the shaft and rotates around the shaft in the horizontal direction, and is connected to the The second sample holder at the other end of the second telescopic delivery arm carries the sample to be tested. 9. The scanning electron microscope according to any one of claims 1-8, wherein a second optical microscope is arranged above the second chamber, and the top of the second chamber is connected to the second chamber. The optical microscope is provided with a second observation window at a vertically opposite position to allow beam transmission. 10. A detection method of a fully automated scanning electron microscope, characterized in that the method comprises: The optical navigation system is used for optical detection of the sample to be tested, and the overall navigation map of the surface of the sample to be tested is obtained; The sample to be tested in the first chamber is transferred to the second chamber through the vacuum valve through the automatic transfer device; Based on the overall navigation map of the surface of the sample to be measured, locate the designated position of the sample to be measured, and use a scanning electron microscope device to perform scanning electron microscope detection on the designated position of the sample to be measured, to obtain the designated position of the sample to be measured information at 11. The method according to claim 10, characterized in that, while performing optical detection on the sample to be tested, the method further comprises: The first and second chambers are evacuated to a vacuum state. 12. The method according to claim 10, characterized in that, before the optical detection of the sample to be tested, the method further comprises: The sample to be tested is placed in the first chamber through the sample changing door of the first chamber to perform the optical detection. 13. The method according to claim 10, wherein said moving the sample to be tested in the first chamber to the second chamber through the vacuum valve through the automatic transfer device comprises: The automatic transfer device moves the sample to be tested to the second chamber through the opened vacuum valve through translation, or through translation and rotation; the sample stage in the second chamber moves to the bottom of the sample holder of the automatic transfer device, The sample to be tested is lifted up, and the sample to be tested is fixed by an automatic fixing device on the sample stage. 14. The method according to claim 10, characterized in that, when the designated position of the sample to be tested is detected by a scanning electron microscope, the method further comprises: The height of the surface of the sample to be tested is measured in real time by the automatic focus tracking system, and the height of the sample stage in the second chamber is adjusted based on the measurement result, so that the electron beam is focused on the surface of the sample to be tested in real time. 15. The method according to any one of claims 10-14, characterized in that, after the sample to be tested is moved to the second chamber, and before scanning electron microscope detection, the method further comprises: The second optical microscope above the second chamber is used to check whether the position of the sample to be tested on the sample stage is correct through the second observation window on the top of the second chamber.