阅读说明：本技术 带电粒子束系统和使用扫描电子显微镜的试样测定方法 (Charged particle beam system and sample measurement method using scanning electron microscope ) 是由 根本佳和 村上雄大 前多崇邦 阿部圣 川本将嗣 目崎洋贵 于 2020-01-30 设计创作，主要内容包括：一种带电粒子束系统和使用扫描电子显微镜的试样测定方法,基于对试样(30)的三维形状计测的结果,生成表示包含试样(30)的试样单元(26)的三维形状的第1形状数据。另一方面,生成表示存在于试样室(18)内的结构物的三维形状的第2形状数据。基于第1形状数据和第2形状数据来控制试样单元(26)的移动,以使试样单元(26)不与结构物发生碰撞。(A charged particle beam system and a sample measurement method using a scanning electron microscope generate 1 st shape data indicating the three-dimensional shape of a sample cell (26) including a sample (30) based on the result of measuring the three-dimensional shape of the sample (30). On the other hand, 2 nd shape data indicating the three-dimensional shape of the structure existing in the sample chamber (18) is generated. The movement of the sample cell (26) is controlled based on the 1 st shape data and the 2 nd shape data so that the sample cell (26) does not collide with the structure.)

1. A charged particle beam system, comprising:

a 1 st shape data generating unit that generates 1 st shape data indicating a three-dimensional shape of a sample based on a result of measuring the three-dimensional shape of the sample;

a sample chamber in which a sample cell containing the sample is disposed and which performs measurement using a charged particle beam;

a 2 nd shape data generating unit that generates 2 nd shape data indicating a three-dimensional shape of a structure present in the sample chamber; and

and a control unit that controls movement of the sample cell in the sample chamber based on the 1 st shape data and the 2 nd shape data.

2. The charged-particle beam system of claim 1,

the control unit controls movement of the sample cell in the sample chamber so that the sample cell does not collide with the structure.

3. The charged-particle beam system of claim 2,

the control unit includes:

a simulation unit that executes a simulation of virtually trying to move the sample cell based on movement information of the sample cell before the sample cell moves in the sample chamber; and

a determination unit that determines a collision between the sample cell and the structure based on an execution result of the simulation,

and prohibiting movement of the sample cell when the collision is determined.

4. The charged-particle beam system of claim 1,

the 1 st shape data is data indicating a three-dimensional shape of the sample cell including the sample and a holder for holding the sample.

5. The charged-particle beam system of claim 1,

the structure includes at least 1 standard element fixedly disposed in the sample chamber.

6. The charged-particle beam system of claim 5,

a port set is provided in the sample chamber,

when the optional elements are used, 1 or more optional elements are provided for 1 or more used ports selected from the above-mentioned port group,

when the optional elements are used, the structure may include 1 or more optional elements.

7. The charged-particle beam system of claim 6,

comprises the following steps:

a 1 st storage unit that stores a plurality of shape data indicating three-dimensional shapes of a plurality of standard elements fixedly arranged in the sample chamber;

a 2 nd storage unit that stores a plurality of shape data indicating a three-dimensional shape of a plurality of optional elements that can be provided to the port group; and

a 3 rd storage unit for storing a port management table for managing 1 or more use ports selected from the port group and 1 or more optional elements provided in the 1 or more use ports,

the 2 nd shape data generating means generates the 2 nd shape data by referring to the 1 st storage unit, the 2 nd storage unit, and the 3 rd storage unit.

8. The charged particle beam system of claim 1, comprising:

a simulated image generating unit that generates a simulated image indicating a spatial relationship between the structure and the sample cell based on the movement information of the sample cell, the 1 st shape data, and the 2 nd shape data; and

and a display unit which displays the analog image.

9. The charged-particle beam system of claim 8,

the simulation image generating means updates the simulation image in accordance with the update of the movement information of the sample cell.

10. The charged-particle beam system of claim 8,

the pseudo image includes a sample cell object corresponding to the sample cell and a structure object corresponding to the structure,

the simulation image generating means reflects the determination result to at least one of the sample cell object and the structure object when the collision between the sample cell and the structure object is determined before the movement of the sample cell.

11. A method for measuring a sample using a scanning electron microscope, comprising:

a step of measuring a three-dimensional shape of a sample before or after arranging a sample cell containing the sample in a sample chamber of a scanning electron microscope;

generating 1 st shape data indicating a three-dimensional shape of the sample based on a result of the three-dimensional shape measurement;

generating 2 nd shape data indicating a three-dimensional shape of a structure present in the sample chamber;

controlling movement of the sample cell in the sample chamber based on the 1 st shape data and the 2 nd shape data; and

and observing the sample using an electron beam after the sample cell moves in the sample chamber.

Technical Field

The present invention relates to a charged particle beam (charged particle beam) system and a sample measurement method using a scanning electron microscope (scanning electron microscope), and more particularly to control of movement of a sample (sample) in a sample chamber (sample chamber).

Background

The charged particle beam system is a system for measuring a sample using charged particles such as electrons and ions. As a representative charged particle beam system, a scanning electron microscope system is known. The scanning electron microscope system is constituted as a single scanning electron microscope apparatus, or is constituted as a combination of the scanning electron microscope apparatus and another apparatus.

In a scanning electron microscope apparatus, a sample cell including a sample and a holder (holder) is placed on a stage in a sample chamber before observing the sample. The stage includes, for example, a vertical mechanism, a tilting mechanism, a 1 st horizontal movement mechanism, a 2 nd horizontal movement mechanism, a rotation mechanism, and the like. Generally, when a sample is observed, the sample is close to the objective lens.

In the charged particle beam apparatus described in japanese patent No. 5537737, an optical image of a sample is synthesized with a pseudo image of a sample stage to generate a synthesized image. The composite image does not reflect the three-dimensional shape of the sample. In the charged particle beam apparatus described in japanese unexamined patent publication No. 2014-93283, the size of a sample is calculated. The dimensions are those of a cylinder surrounding the entire sample. The actual three-dimensional shape of the sample was not measured.

Disclosure of Invention

Problems to be solved by the invention

In the charged particle beam system, when the sample cell is moved in the sample chamber, it is necessary to avoid collision between the sample cell (particularly, the sample) and a structure present in the sample chamber. Therefore, conventionally, the movement condition of the sample that does not collide is determined based on the maximum height of the sample input by the user. However, this does not take into account the actual three-dimensional shape of the sample. According to the above-described conventional technique, there are problems that a collision occurs due to an input error of the maximum height, a user load is caused by inputting the maximum height, and the collision cannot be performed even in a situation where the sample can be brought close to the objective lens.

The purpose of the present invention is to realize control of movement of a sample in consideration of the three-dimensional shape of the sample in a charged particle beam system.

Means for solving the problems

Drawings

Fig. 1 is a schematic diagram showing an example of the configuration of a charged particle beam system according to an embodiment.

Fig. 2 is a block diagram showing an example of the configuration of the arithmetic control device.

Fig. 3 is a diagram showing an example of the holder shape database.

Fig. 4 is a diagram showing an example of the standard element shape database.

Fig. 5 is a diagram showing an example of the optional element shape database.

Fig. 6 is a diagram showing an example of the port management table.

Fig. 7 is a diagram showing an example of the image management table.

Fig. 8 is a diagram showing an example of a display image.

Fig. 9 is a flowchart showing an example of the 1 st operation.

Fig. 10 is a diagram showing a 1 st example of the collision expression method.

Fig. 11 is a diagram showing a 2 nd example of the collision expression method.

Fig. 12 is a diagram illustrating a modification of the shape measurement method.

Fig. 13 is a flowchart showing an example of the 2 nd operation.

A charged particle beam system according to an embodiment is characterized by comprising: a 1 st shape data generating unit that generates 1 st shape data indicating a three-dimensional shape of a sample based on a result of measuring the three-dimensional shape of the sample; a sample chamber in which a sample cell containing the sample is disposed and which performs measurement using a charged particle beam; a 2 nd shape data generating unit that generates 2 nd shape data indicating a three-dimensional shape of a structure present in the sample chamber; and a control unit that controls movement of the sample cell in the sample chamber based on the 1 st shape data and the 2 nd shape data.

According to the above configuration, the movement of the sample cell can be controlled based on the three-dimensional shape of the sample and the three-dimensional shape of the structure. Therefore, for example, when the sample cell is expected to approach or collide with the structure, the movement of the sample cell can be restricted, or the positioning of the sample cell can be optimized. Specifically, the sample is made closer to the objective lens. If the user does not need to input the height of the sample, the burden on the user can be reduced.

In the above configuration, the three-dimensional shape of the sample does not mean a three-dimensional shape of a three-dimensional figure enclosing the entire sample, but means a specific three-dimensional shape of the sample or an actual three-dimensional shape of the sample. For example, when the sample is composed of a plurality of sample elements, the three-dimensional shape of the sample is measured at least to the extent that the substantial form of each sample element can be recognized individually. When it is desired to perform movement control with high accuracy, the three-dimensional shape of the sample needs to be measured with high accuracy.

In an embodiment, the control unit controls movement of the sample cell in the sample chamber so that the sample cell does not collide with the structure. According to this configuration, the sample cell is prevented from colliding with the structure. The concept of movement includes a change in position and a change in posture. The three-dimensional shape measurement of the sample can be performed outside the sample chamber or inside the sample chamber. The three-dimensional shape measurement of the sample may be performed in a space adjacent to the sample chamber.

In an embodiment, the control unit includes: a simulation unit that executes a simulation of virtually trying to move the sample cell based on movement information of the sample cell before the sample cell moves in the sample chamber; and a determination unit configured to determine a collision between the sample cell and the structure based on a result of execution of the simulation, and to prohibit movement of the sample cell when the collision is determined. According to this configuration, even if the sample cell and the structure have complicated shapes or even if the movement of the sample cell is complicated, it is possible to relatively easily determine the collision. It is also possible to determine a theoretical collision while taking into account the margin. The concept of the movement information of the sample unit includes the movement information of the stage.

In an embodiment, the 1 st shape data is data indicating a three-dimensional shape of the sample cell including the sample and a holder holding the sample. Generally, a sample is processed together with a holder that carries the sample. Therefore, it is reasonable to process the shape data in units of sample cells. Generally, a plurality of holders are prepared, and a holder selected from among them is used. In view of this, it is also possible to prepare a plurality of shape data corresponding to a plurality of kinds of holders in advance, and generate the 1 st shape data using the shape data selected from among them.

In an embodiment, the structure includes at least 1 standard element fixedly disposed in the sample chamber. For example, in a scanning electron microscope system, a reflected electron detector (back electron detector), a secondary electron detector (secondary electron detector), and the like are used as standard elements. The stage, the inner wall of the sample chamber, and the like may be used as standard elements.

In an embodiment, the sample chamber is provided with a port group, 1 or more optional elements are provided to 1 or more use ports selected from the port group when the optional elements are used, and the structure includes the 1 or more optional elements when the optional elements are used. According to the above configuration, when 1 or more optional elements are used, the 2 nd shape data can be generated in consideration of them, and the movement of the sample cell can be controlled based on the generated data. That is, when the optional element is used, the sample cell can be prevented from colliding with the optional element. For example, in a scanning electron microscope system, an X-ray detector, a nozzle, and the like can be given as optional elements.