JP2021107807A5

JP2021107807A5 -

Info

Publication number: JP2021107807A5
Application number: JP2020194644A
Authority: JP
Filing date: 2020-11-24
Publication date: 2023-10-27
Anticipated expiration: 2040-11-24

Description

上述の荷電粒子ビーム検査装置において、荷電粒子ビームで照射可能な測定用画素サイズをＰＳ、第２の方向又は第２の方向の逆方向における第２ビーム整定時間Ｏｆｓ＿ｖを含む、第２の方向又は第２の方向の逆方向のビームスキャン時間をＴｖとしたときに、ステージの移動速度ＶはＶ＝ＰＳＮ／（２Ｔｖ）であることが好ましい。 In the above-mentioned charged particle beam inspection apparatus, the measurement pixel size that can be irradiated with the charged particle beam is defined as PS, the second direction or the second direction including the second beam settling time Ofs_v in the second direction or the opposite direction of the second direction. Preferably, the moving speed V of the stage is V=PS N /(2Tv), where Tv is the beam scanning time in the opposite direction to the second direction.

ｙ方向又は－ｙ方向における第２ビーム整定時間Ｏｆｓ＿ｖを含む、ｙ方向又は－ｙ方向のビームスキャン時間をＴｖとしたときに、ＸＹステージ１０５の移動速度ＶはＶ＝ＰＳＮ／（２Ｔｖ）である。これは、以下のようにして導かれる。まず、１本のビームが担当するグリッド２９の面積は、（ｐ／Ｍ）×ｐである。この（ｐ／Ｍ）×ｐであるグリッド２９におけるビームスキャンが開始されてから完了するまでにＸＹステージ１０５が移動する距離は、段落００３５に記載したとおりＮ／Ｍ・ｐである。次に、測定用画素２８のｘ方向及びｙ方向におけるサイズをＰＳとして、ｙ方向のビームスキャンに必要な時間をＴｖとする。この場合、ｙ方向のスキャン時間は（ｐ／（Ｍ×ＰＳ））×Ｔｖで求められる。すると、図９及び図１０にて示したように、ｙ方向において極性を変えて（ｙ方向及び－ｙ方向）２回スキャンを行うため、（（ｐ／（Ｍ×ＰＳ））×Ｔｖ×２）×Ｖ＝Ｎ／Ｍ・ｐという式が成立する。よって、Ｖ＝ＰＳＮ／（２Ｔｖ））である。なお、上述のＸＹステージ１０５の移動速度Ｖは、例えば、移動速度計算回路１４６により計算される。 When the beam scanning time in the y direction or -y direction including the second beam settling time Ofs_v in the y direction or -y direction is Tv, the moving speed V of the XY stage 105 is V=PS N /(2Tv). be. This is derived as follows. First, the area of the grid 29 covered by one beam is (p/M)×p. The distance that the XY stage 105 moves from the start to the completion of the beam scan in the grid 29, which is (p/M)×p, is N/M·p as described in paragraph 0035 . Next, let PS be the size of the measurement pixel 28 in the x direction and the y direction, and let Tv be the time required for beam scanning in the y direction. In this case, the scan time in the y direction is determined by (p/(M×PS))×Tv. Then, as shown in FIGS. 9 and 10, since scanning is performed twice with changing polarity in the y direction (y direction and -y direction), ((p/(M×PS))×Tv×2 )×V= N/M·p holds true. Therefore, V=PS N /(2Tv)). Note that the above-mentioned moving speed V of the XY stage 105 is calculated by, for example, the moving speed calculation circuit 146.

ｘ方向又は－ｘ方向における第１ビーム整定時間Ｏｆｓ＿ｈを含む、ｘ方向又は－ｘ方向のビームスキャン時間をＴｈ、ｙ方向又は－ｙ方向における第２ビーム整定時間Ｏｆｓ＿ｖを含む、ｙ方向又は－ｙ方向のビームスキャン時間をＴｖとしたときに、ＸＹステージ１０５の移動速度ＶはＶ＝ＰＳＮ／（２×（Ｍ×Ｔｈ＋Ｔｖ））である。これは、以下のようにして導かれる。まず、１本のビームが担当するグリッド２９の面積は、（ｐ／Ｍ）×ｐである。この（ｐ／Ｍ）×ｐであるグリッド２９におけるビームスキャンが開始されてから完了するまでにＸＹステージ１０５が移動する距離は、段落００３５に記載したとおりＮ／Ｍ・ｐである。次に、測定用画素２８のｘ方向及びｙ方向におけるサイズをＰＳとして、ｘ方向のビームスキャンに必要な時間をＴｈ、ｙ方向のビームスキャンに必要な時間をＴｖとする。この場合、ｘ方向のスキャン時間は（ｐ／ＰＳ）×Ｔｈで求められる。また、ｙ方向のスキャン時間は（ｐ／（Ｍ×ＰＳ））×Ｔｖで求められる。すると、図１１ないし図１４にて示したように、ｘ方向において極性を変えて（ｘ方向及び－ｘ方向）２回スキャンを行い、ｙ方向において極性を変えて（ｙ方向及び－ｙ方向）２回スキャンを行うため、（（ｐ／（Ｍ×ＰＳ））×Ｔｖ×２＋（ｐ／ＰＳ）×Ｔｈ×２）×Ｖ＝Ｎ／Ｍ・ｐという式が成立する。よって、Ｖ＝ＰＳＮ／（２×（Ｍ×Ｔｈ＋Ｔｖ））である。なお、上述のＸＹステージ１０５の移動速度Ｖは、例えば、移動速度計算回路１４６により計算される。 Beam scanning time in the x direction or -x direction, including the first beam settling time Ofs_h in the x direction or -x direction, Th, including the second beam settling time Ofs_v in the y direction or -y direction, in the y direction or -y When the beam scanning time in the direction is Tv, the moving speed V of the XY stage 105 is V=PS N /(2×(M×Th+Tv)). This is derived as follows. First, the area of the grid 29 covered by one beam is (p/M)×p. The distance that the XY stage 105 moves from the start to the completion of the beam scan in the grid 29, which is (p/M)×p, is N/M·p as described in paragraph 0035 . Next, the size of the measurement pixel 28 in the x and y directions is set as PS, the time required for beam scanning in the x direction is Th, and the time required for beam scanning in the y direction is set as Tv. In this case, the scan time in the x direction is determined by (p/PS)×Th. Further, the scan time in the y direction is determined by (p/(M×PS))×Tv. Then, as shown in FIGS. 11 to 14, scanning is performed twice by changing the polarity in the x direction (x direction and -x direction), and by changing the polarity in the y direction (y direction and -y direction). Since scanning is performed twice, the formula ((p/(M×PS))×Tv×2+(p/PS)×Th×2)×V= N/M·p holds true. Therefore, V=PS N /(2×(M×Th+Tv)). Note that the above-mentioned moving speed V of the XY stage 105 is calculated by, for example, the moving speed calculating circuit 146.

Claims

a movable stage on which the substrate is placed;
a stage control circuit that continuously moves the stage in a direction opposite to the first direction;
N rows (N is an integer of 2 or more) at the same pitch p on the substrate surface in the first direction and N' rows (N' is an integer of 1 or more) in a second direction orthogonal to the first direction. ) Using a multi-beam composed of a plurality of lined up charged particle beams, the inspection area of the substrate has a size obtained by p/M (M is an integer of 2 or more) in the first direction and in the second direction. N×N' small areas on the substrate arranged at the pitch p in the first direction and N' in the second direction among a plurality of small areas divided into a predetermined size. Deflecting the multi-beams at once into a group so as to follow the continuous movement of the stage while the stage continuously moves a distance obtained by N/M·p in the opposite direction to the first direction. While tracking deflection of the multi-beam, the movement of the stage from the N×N' small area group in the opposite direction to the first direction is completed, Tracking reset is performed by collectively re-deflecting the multi-beams to a new group of N×N' small regions arranged at the pitch p in the first direction and N spaces apart in the first direction. The first function and
While the multi-beams are being tracking deflected to follow the continuous movement of the stage, each of the multi-beams is directed to each of the plurality of small areas,
The end point of each of the plurality of small regions on the side opposite to the first direction is the starting point, and the end point of each of the plurality of small regions on the side of the first direction is the end point. , a first step in which the collective deflection of the multi-beams along the second direction is repeatedly performed from an end on a side opposite to the first direction toward an end on a side in the first direction; Perform the process, and then
The end point of each of the plurality of small regions on the side opposite to the first direction is the starting point, and the end point of each of the plurality of small regions on the side of the first direction is the end point. , repeatedly deflecting the multi-beams in a direction opposite to the second direction from an end opposite to the first direction toward an end opposite the first direction; By performing the second step,
a deflector having two functions, a second function of deflecting the multi-beams all at once so as to scan the N×N′ small area group;
a detector that detects secondary electrons emitted from the substrate due to irradiation of the multi-beam to the substrate;
Equipped with
A charged particle beam inspection apparatus characterized in that, as the value of N and the value of M, a combination of values such that the greatest common divisor between the value of N and the value of M is 1 is used.

the second direction or the second direction, including a measurement pixel size PS that can be irradiated with the charged particle beam, and a second beam settling time Ofs_v in the second direction or a direction opposite to the second direction; When the beam scan time in the opposite direction is Tv,
The moving speed V of the stage is V=PS N /(2Tv)
The charged particle beam inspection apparatus according to claim 1.

When the measurement pixel size that can be irradiated with the charged particle beam is PS, and the scan frequency of the charged particle beam is f,
The beam scanning time Tv in the second direction or the opposite direction to the second direction is Tv=(p/PS)×(p/M/PS)×(1/f)+(p/M/PS)× Ofs_v
The charged particle beam inspection apparatus according to claim 1.

Average image acquisition for obtaining an average secondary electron image obtained by averaging the first secondary electron image acquired in the first step and the second secondary electron image acquired in the second step. The charged particle beam inspection apparatus according to claim 1, further comprising a circuit.

a movable stage on which the substrate is placed;
a stage control circuit that continuously moves the stage in a direction opposite to the first direction;
N rows (N is an integer of 2 or more) at the same pitch p on the substrate surface in the first direction and N' rows (N' is an integer of 1 or more) in a second direction orthogonal to the first direction. ) Using a multi-beam composed of a plurality of lined up charged particle beams, the inspection area of the substrate has a size obtained by p/M (M is an integer of 2 or more) in the first direction and in the second direction. N×N' small areas on the substrate arranged at the pitch p in the first direction and N' in the second direction among a plurality of small areas divided into a predetermined size. Deflecting the multi-beams at once into a group so as to follow the continuous movement of the stage while the stage continuously moves a distance obtained by N/M·p in the opposite direction to the first direction. While tracking deflection of the multi-beam, the movement of the stage from the N×N' small area group in the opposite direction to the first direction is completed, Tracking reset is performed by collectively re-deflecting the multi-beams to a new group of N×N' small regions arranged at the pitch p in the first direction and N spaces apart in the first direction. The first function and
While the multi-beams are being tracking deflected to follow the continuous movement of the stage, each of the multi-beams is directed to each of the plurality of small areas,
The end point of each of the plurality of small regions on the side opposite to the first direction is the starting point, and the end point of each of the plurality of small regions on the side of the first direction is the end point. , a first step in which the collective deflection of the multi-beams along the second direction is repeatedly performed from an end on a side opposite to the first direction toward an end on a side in the first direction; Perform the process, and then
A second step of repeatedly deflecting the multi-beams in a direction opposite to the first direction is performed, and then,
A third step is performed in which the collective deflection of the multi-beams along the first direction is repeatedly performed, and then,
The end point of each of the plurality of small regions on the side opposite to the first direction is the starting point, and the end point of each of the plurality of small regions on the side of the first direction is the end point. , repeatedly deflecting the multi-beams in a direction opposite to the second direction from an end opposite to the first direction toward an end opposite the first direction; By performing the fourth step,
a deflector having two functions, a second function of deflecting the multi-beams all at once so as to scan the N×N′ small area group;
a detector that detects secondary electrons emitted from the substrate due to irradiation of the multi-beam to the substrate;
Equipped with
A charged particle beam inspection apparatus characterized in that, as the value of N and the value of M, a combination of values such that the greatest common divisor between the value of N and the value of M is 1 is used.

The charged particle beam inspection according to claim 5, wherein the collective deflection of the multi-beams in the second step is repeatedly performed from a side opposite to the second direction to a side in the second direction. Device.

The charged particle beam inspection according to claim 5, wherein the collective deflection of the multi-beams in the second step is repeatedly performed from the side in the second direction to the side in the opposite direction to the second direction. Device.

The measurement pixel size that can be irradiated with the charged particle beam is PS,
Th, a beam scanning time in the first direction or in the opposite direction to the first direction, including a first beam settling time Ofs_h in the first direction or in the opposite direction to the first direction;
When Tv is the beam scanning time in the second direction or in the opposite direction to the second direction, including the second beam settling time Ofs_v in the second direction or in the opposite direction to the second direction,
The moving speed V of the stage is V=PS N /(2×(M×Th+Tv))
The charged particle beam inspection apparatus according to claim 5.

When the measurement pixel size that can be irradiated with the charged particle beam is PS, and the scan frequency of the charged particle beam is f,
The beam scanning time Th in the first direction or in the opposite direction to the first direction is Th=(p/PS)×(p/M/PS)×(1/f)+(p/PS)×Ofs_h
and
The beam scanning time Tv in the second direction or the opposite direction to the second direction is Tv=(p/PS)×(p/M/PS)×(1/f)+(p/M/PS)× Ofs_v
The charged particle beam inspection apparatus according to claim 5.

A first secondary electron image obtained in the first step, a second secondary electron image obtained in the second step, and a third secondary electron image obtained in the third step. The charged particle beam inspection apparatus according to claim 5, further comprising an average image acquisition circuit that acquires an average secondary electron image obtained by averaging the electronic image and the fourth secondary electron image acquired in the fourth step. .

Arranged in N rows (N is an integer of 2 or more) at the same pitch p on the substrate surface in a first direction and in N' rows (N' is an integer of 1 or more) in a second direction perpendicular to the first direction. Using a multi-beam composed of a plurality of charged particle beams, the inspection area of the substrate has a size obtained by p/M (M is an integer of 2 or more) in the first direction and a predetermined size in the second direction. Among the plurality of small regions divided by size, N×N' small regions on the substrate are arranged at the pitch p in the first direction and N' in the second direction. The multi-beams are deflected all at once to follow the continuous movement of the stage on which the substrate is placed while it continuously moves a distance obtained by N/M·p in the opposite direction to the first direction. While tracking and deflecting the multi-beam,
each of the multi-beams in each of the plurality of small areas,
The end point of each of the plurality of small regions on the side opposite to the first direction is the starting point, and the end point of each of the plurality of small regions on the side of the first direction is the end point. , a first step in which the collective deflection of the multi-beams along the second direction is repeatedly performed from an end on a side opposite to the first direction toward an end on a side in the first direction; Perform the process, and then
The end point of each of the plurality of small regions on the side opposite to the first direction is the starting point, and the end point of each of the plurality of small regions on the side of the first direction is the end point. , repeatedly deflecting the multi-beams in a direction opposite to the second direction from an end opposite to the first direction toward an end opposite the first direction; By performing the second step,
detecting secondary electrons emitted from the substrate due to irradiation of the multi-beam to the substrate;
By the time the stage has completed moving a distance obtained by N/M·p in the opposite direction to the first direction, the stage has moved away from the group of N×N′ small regions by N in the first direction. , a charged particle beam inspection method that performs a tracking reset by collectively re-deflecting the multi-beam to a new group of N×N' small regions arranged at the pitch p in the first direction,
A charged particle beam inspection method using, as the value of N and the value of M, a combination of values such that the greatest common divisor between the value of N and the value of M is 1.

the second direction or the second direction, including a measurement pixel size PS that can be irradiated with the charged particle beam, and a second beam settling time Ofs_v in the second direction or a direction opposite to the second direction; When the beam scan time in the opposite direction is Tv,
The moving speed V of the stage is V=PS N /(2Tv)
The charged particle beam inspection method according to claim 11.

When the measurement pixel size that can be irradiated with the charged particle beam is PS, and the scan frequency of the charged particle beam is f,
The beam scanning time Tv in the second direction or the opposite direction to the second direction is Tv=(p/PS)×(p/M/PS)×(1/f)+(p/M/PS)× Ofs_v
The charged particle beam inspection method according to claim 11.

11. An average secondary electron image is obtained by averaging the first secondary electron image obtained in the first step and the second secondary electron image obtained in the second step. The charged particle beam inspection device described.

Arranged in N rows (N is an integer of 2 or more) at the same pitch p on the substrate surface in a first direction and in N' rows (N' is an integer of 1 or more) in a second direction perpendicular to the first direction. Using a multi-beam composed of a plurality of charged particle beams, the inspection area of the substrate has a size obtained by p/M (M is an integer of 2 or more) in the first direction and a predetermined size in the second direction. Among the plurality of small regions divided by size, N×N' small regions on the substrate are arranged at the pitch p in the first direction and N' in the second direction. The multi-beams are deflected all at once to follow the continuous movement of the stage on which the substrate is placed while it continuously moves a distance obtained by N/M·p in the opposite direction to the first direction. While tracking and deflecting the multi-beam,
each of the multi-beams in each of the plurality of small areas,
The end point of each of the plurality of small regions on the side opposite to the first direction is the starting point, and the end point of each of the plurality of small regions on the side of the first direction is the end point. , a first step in which the collective deflection of the multi-beams along the second direction is repeatedly performed from an end on a side opposite to the first direction toward an end on a side in the first direction; Perform the process, and then
A second step of repeatedly deflecting the multi-beams in a direction opposite to the first direction is performed, and then,
A third step of repeatedly deflecting the multi-beams in a direction opposite to the first direction is performed, and then,
The end point of each of the plurality of small regions on the side opposite to the first direction is the starting point, and the end point of each of the plurality of small regions on the side of the first direction is the end point. , repeatedly deflecting the multi-beams in a direction opposite to the second direction from an end opposite to the first direction toward an end opposite the first direction; By performing the fourth step,
detecting secondary electrons emitted from the substrate due to irradiation of the multi-beam to the substrate;
By the time the stage has completed moving a distance obtained by N/M·p in the opposite direction to the first direction, the stage has moved away from the group of N×N′ small regions by N in the first direction. , a charged particle beam inspection method that performs a tracking reset by collectively re-deflecting the multi-beam to a new group of N×N' small regions arranged at the pitch p in the first direction,
A charged particle beam inspection method using, as the value of N and the value of M, a combination of values such that the greatest common divisor between the value of N and the value of M is 1.

The charged particle beam inspection according to claim 15, wherein the collective deflection of the multi-beams in the second step is repeatedly performed from a side opposite to the second direction to a side in the second direction. Method.

The charged particle beam inspection according to claim 15, wherein the collective deflection of the multi-beams in the second step is repeatedly performed from the side in the second direction to the side in the opposite direction to the second direction. Method.

The measurement pixel size that can be irradiated with the charged particle beam is PS,
Th, a beam scanning time in the first direction or in the opposite direction to the first direction, including a first beam settling time Ofs_h in the first direction or in the opposite direction to the first direction;
When Tv is the beam scanning time in the second direction or in the opposite direction to the second direction, including the second beam settling time Ofs_v in the second direction or in the opposite direction to the second direction,
The moving speed V of the stage is V=PS N /(2×(M×Th+Tv))
The charged particle beam inspection method according to claim 15.

When the measurement pixel size that can be irradiated with the charged particle beam is PS, and the scan frequency of the charged particle beam is f,
The beam scanning time Th in the first direction or in the opposite direction to the first direction is Th=(p/PS)×(p/M/PS)×(1/f)+(p/PS)×Ofs_h
and
The beam scanning time Tv in the second direction or the opposite direction to the second direction is Tv=(p/PS)×(p/M/PS)×(1/f)+(p/M/PS)× Ofs_v
The charged particle beam inspection method according to claim 15.

A first secondary electron image obtained in the first step, a second secondary electron image obtained in the second step, and a third secondary electron image obtained in the third step. 16. The charged particle beam inspection method according to claim 15, wherein an average secondary electron image is obtained by averaging the electron image and the fourth secondary electron image obtained in the fourth step.