JPH02184748A - Substrate inspection device using electron beam - Google Patents

Abstract

PURPOSE:To eliminate a difference in secondary electron beam detection rate with an inspection position and to perform high-accuracy inspection by providing a control grid with a slit and a table. CONSTITUTION:A substrate 10 to be inspected is irradiated with an electron beam with which scanning is executed in an X direction through the slit 5 of the control grid 6. Then when the electron beam strikes on a conductor on the substrate 10, secondary electrons are emitted. The secondary electrons pass through the grid 6 and are detected by secondary electron detectors 7a-7n. Further, the grid 6 prevents the secondary electrons from sticking on the substrate 10 again. Further, the entire surface of the substrate 10 is inspected by the table 9 which moves at right angle to the electron beam with which scanning is executed in the X direction. Thus, the difference in secondary electron detection rate with an inspection position is eliminated to improve the inspection accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a board inspection device using an electron beam, and in particular, to non-contact measurement of the electrical characteristics of conductor wiring patterns formed inside and on the surface of an insulator. , relates to a board inspection device using an electron beam.

[Conventional technology]

As a conventional technique, for example, Japanese Patent Publication No. 61-17066
There is an inspection technique as shown in Publication No. 9.

Next, a conventional substrate inspection apparatus using an electron beam will be described in detail with reference to the drawings.

FIG. 2 is a schematic diagram showing an example of a conventional board inspection apparatus using an electron beam.

The substrate inspection apparatus using an electron beam shown in FIG. 2 includes: (A) a vacuum chamber 1 that accommodates a substrate to be inspected 10; (II) an electron optical column 2 that generates an electron beam to irradiate the substrate to be inspected 10; (C) A control unit 23 connected to the electron optical lens barrel 2 and having a beam on/off circuit, a scanning circuit in the X direction, and a focusing control circuit; (D) a secondary electron detector 25; (E) A signal processing unit 26 that processes the detection signal of the secondary electron detector 25; (F) A table 27 on which the substrate to be inspected 10 is mounted and moves in the x, y, and z directions; (G) A control unit 23 and a signal processing unit 26; section 26 and table 27
A central control unit 30 that controls the following.

When the beam irradiated onto the substrate 10 to be inspected from the electron optical column 2 hits a conductor on the substrate 10 to be inspected, secondary electrons are emitted.

These secondary electrons are located in the upper part of the substrate 10 to be inspected and in the vacuum chamber 1.
is detected by a secondary electron detector 25 attached to the side of the

The position where the electron beam is applied is determined by the control section 23 of the electron optical lens barrel 2.
However, if the size of the substrate 10 to be inspected is large, the position to be irradiated with the electron beam is determined by moving the table 27.

[Problem to be solved by the invention]

In the above-mentioned conventional board inspection equipment using an electron beam, the positional relationship between the electron beam irradiation position and the secondary electron detector is not constant, and the secondary electron It is difficult to detect secondary electrons that emit electrons in different directions, and the detection accuracy is poor.

[Means to solve the problem]

A substrate inspection apparatus using an electron beam according to the present invention includes: (A) a vacuum chamber that accommodates a substrate to be inspected; (B) an electron optical column that generates an electron beam to irradiate the substrate to be inspected; (C) the electron beam Connected to the optical barrel, beam-on
a control unit having an off-circuit, an X-direction scanning circuit, and a focusing control circuit; (D) a control unit located between the substrate to be inspected and the electron optical lens barrel; (E) a control grid having a slit in a portion irradiated with the scanned electron beam; (E) a plurality of control grids arranged in the X direction, located between the electron optical lens barrel and the control grid, located on both sides of the slit; (F) a signal processing unit that processes the detection signal of the secondary electron detector; (G) the substrate to be inspected is mounted and scanned in the X direction generated from the electron optical lens barrel; a table that moves in the X direction perpendicular to the electron beam; (H) the control unit;
The device includes: the signal processing unit; and a central control unit that controls the table.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

The substrate inspection apparatus using an electron beam shown in FIG. 1 includes: (A) a vacuum chamber 1 that accommodates a substrate to be inspected 10; (B) an electron optical column 2 that generates an electron beam to irradiate the substrate to be inspected 10; (C) A control unit 3 connected to the electron optical lens barrel 2 and having a beam on/off circuit, a scanning circuit in the X direction, and a focusing control circuit; (D) A substrate to be inspected 10 and the electron optical lens barrel 2 (IE) A control grid 6 is located between the electron optical lens barrel 2 and the control grid 6, and has a slit 5 in the part that is irradiated with the electron beam scanned in the X direction from the electron optical lens barrel 2. and located on both sides of the slit 5,
a plurality of secondary electron detectors 7a to 7n arranged in the direction; (F) a signal processing section 8 that processes detection signals of the secondary electron detectors 7a to 7n; (G) an electron optical a table 9 that moves in the Y direction perpendicular to the electron beam scanned in the X direction generated from the lens barrel 2; (H) a central control unit that controls the control unit 3, the signal processing unit 8, and the table 9; 11
It consists of , and.

The electron beam scanning in the X direction passes through the slit 5 of the control grid 6 and is irradiated onto the substrate 10 to be inspected.

When the electron beam hits the conductor of the substrate 10 to be inspected, secondary electrons are emitted.

This secondary electron passes through the control grid 6 and
It is detected by secondary electron detectors 7a to 7n.

The control grid 6 prevents the aforementioned secondary electrons from adhering to the substrate to be inspected 10 again.

The entire surface of the substrate 10 to be inspected is inspected by a table 9 that moves in a direction perpendicular to the electron beam scanned in the X direction.

〔Effect of the invention〕

The substrate inspection device using an electron beam of the present invention has a control grid having a slit on the top of the substrate to be inspected through which the electron beam scans in the X direction, instead of providing a secondary electron detector on the side of the vacuum chamber. By providing a plurality of secondary electron detectors arranged in the X direction on both sides of the slit between the control grid and the electron optical column, and a table for moving the substrate to be inspected in the Y direction, Since the positional relationship between the position hit by the electron beam and the secondary electron detector is constant, it is possible to eliminate the difference in the secondary electron detection rate depending on the inspection position, which has the effect of improving inspection accuracy.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a conventional example. 1... Vacuum chamber, 2... Electron optical lens barrel,
3...Control unit, 5...Slit, 6.
... Control grid, 7 ... Secondary electron detector, 8 ... Signal processing section, 9 ...
・Table, 10... Board to be inspected, 11...
...Central processing unit. Figure 1 Agent: Susumu Uchihara, patent attorney

Claims (1)

[Claims] (A) A vacuum chamber that accommodates a substrate to be inspected; (B) An electron optical column that generates an electron beam to irradiate the substrate to be inspected; (C) A vacuum chamber that is connected to the electron optical column. Beam on
a control unit having an off-circuit, an X-direction scanning circuit, and a focusing control circuit; (D) a control unit located between the substrate to be inspected and the electron optical lens barrel; (E) a control grid having a slit in a portion irradiated with the scanned electron beam; (E) a plurality of control grids arranged in the X direction, located between the electron optical lens barrel and the control grid, located on both sides of the slit; (F) a signal processing unit that processes the detection signal of the secondary electron detector; (G) the substrate to be inspected is mounted and scanned in the X direction generated from the electron optical lens barrel; a table that moves in the Y direction perpendicular to the electron beam; (H) the control unit;
A substrate inspection apparatus using an electron beam, comprising: a central control section that controls the signal processing section; and the table.