JPS61128221A - Microscope device for semiconductor inspection - Google Patents

Abstract

PURPOSE:To perform inspection as to 'dust' and 'flaw' extremely easily as well as the defect inspection of semiconductor wafers and masks by providing an angle means which reflect light directed to a reflecting within a specific range nearby an ocular and also adjust the angle of incidence. CONSTITUTION:A tungsten lamp 8 is provided where reflected light is directed to the specific range A nearby the ocular 2 so as to carry out the inspection as to 'dust' and 'flaw' simultaneously with the defect inspection of wafers and masks. A fitting position adjusting metallic fixture 9 is provided so as to vary the angle of incidence of the tungsten lamp 8. The whole microscope is slanted by a slanting table 6 so that the ocular side of a mount surface is lowest to the horizontal plane. Then, it is confirmed visually whether or not and where 'dust' or 'flaw' is present, and then the mount table 10 is moved in two dimensions to put the objective 1 in focus so as to magnify and observe the confirmed position through the microscope, but when the stroke is large, defocusing is caused. For the purpose, a positioning mechanism 7 for moving the mount table 10 vertically is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a semiconductor inspection microscope apparatus for inspecting pattern defects in semiconductor wafers, mask defects, etc. in the manufacturing process of integrated circuits.

(Technical background of the invention and its problems) As shown in FIG. 2, this type of conventional microscope consists of an objective lens 1, an eyepiece lens 2, and a halogen lamp 4 that illuminates the object to be inspected through a mirror 3. It consists of an optical system and a stage 10 that has handles 11, 12, etc., and that moves three-dimensionally an adapter 5 to which an object to be inspected is attached.

This microscope is installed so that when a wafer or the like is attached to the adapter 5, the microscope is horizontal, that is, the surface of the stage 10 is horizontal.

Therefore, the optical axis of the objective lens 1 is directed in the vertical direction. In addition, the eyepiece lens 2 is located away from the direction of extension of the optical axis of the objective lens 1 for ease of viewing, and the halogen lamp 4 is located on the opposite side of the eyepiece lens 1 so as not to interfere with observation. ing.

By the way, this microscope irradiates the sample mounting surface of the stage 10 with light from the halogen lamp 4 perpendicularly through the objective lens 1, so it is suitable for inspecting pattern defects on semiconductor wafers and mask defects. However, when it is required to inspect semiconductor wafers or masks for "dust" or "scratches" in addition to these inspections, it is difficult to find the "dust" or "scratches" using the light from the halogen lamp 4. In other words, "dust" or "scratches" on wafers or masks appear to shine when light is irradiated diagonally to the inspection surface.
Since the halogen lamp 4 illuminates the surface to be inspected vertically, even if there is "dust" or "scratches", it will hardly shine. Moreover, since only a very narrow area focused by the objective lens 1 is illuminated, the stage 10 If you don't operate the tool frequently with large strokes, you won't be able to find any dirt or scratches.

(Purpose of the Invention) The present invention has been made in consideration of the above circumstances, and is a method for detecting "dust" and "scratches" in conjunction with defect inspection of semiconductor wafers and masks.
An object of the present invention is to provide a microscope device for semiconductor inspection that can perform inspections extremely easily.

[Summary of the invention]

The present invention for achieving this object has an eyepiece lens located at a position deviated from the direction in which the optical axis of the objective lens extends, and
A microscope comprising a stage capable of moving an object surface in a direction perpendicular to the optical axis of the objective lens, and a microscope having a stage that can move the object surface in a direction perpendicular to the optical axis of the objective lens, and tilting means for tilting the entire microscope by an angle;
When a reflective surface perpendicular to the optical axis is formed at the focal point of the objective lens, angle adjusting means is provided to reflect the light directed toward the reflective surface to a predetermined range near the eyepiece and adjust the incident angle. and a position adjustment means for finely adjusting the position of the object surface or the stage in the vertical direction for focusing.

[Embodiments of the invention]

FIG. 1 is a conceptual diagram showing the configuration of an embodiment of the present invention,
Elements that are the same as those shown in FIG. 2 are given the same reference numerals, and their explanations will be omitted.

Here, the entire microscope shown in FIG. 2 is installed by tilting the microscope so that the eyepiece side of the object surface is the lowest with respect to the horizontal plane. A positioning camera 7 serves as a position adjustment means for finely adjusting the stage 10 in the vertical direction to perform focusing with respect to the optical system such as the halogen lamp 4, and a stage perpendicular to the optical axis of the objective lens 1. A tungsten lamp 8 having a mounting position adjustment fitting 9 as an angle adjustment means is added so that the reflected light directed toward the object surface travels toward a predetermined range near the eyepiece.

The operation of this embodiment configured as described above will be explained below.

First of all, "dust" or [scratches] on wafers and masks are
When the inspection surface is irradiated with light from an oblique direction, it appears to shine, so a tungsten lamp 8 is provided to inspect the presence or absence and position of the inspection surface. In this case, a tungsten lamp 8 is placed at a position where the reflected light is directed in a predetermined range near the eyepiece 2 so that "dust" or "scratches" can be inspected in parallel with the wafer or mask defect inspection. is provided. Note that the predetermined range A referred to here refers to an area where an inspection through the eyepiece 2 and an inspection for "dust" or "scratches" with the naked eye can be performed by only slightly moving the position of the eye. There is.

By the way, when inspecting for "dust" or "grains" attached to the surface, the angle of incidence of the Dungesten lamp 8 has a slight effect, and if the angle deviates slightly, the inspection becomes difficult, so it is necessary to change the angle of incidence. A mounting position adjustment fitting 9 is provided.

On the other hand, when we find "dust" or "scratches" on a wafer or mask, we tilt the inspection surface toward us, but in this case, the eyepiece side of the object surface is the lowest relative to the horizontal plane. The entire microscope is tilted by the tilt table 6 as shown in FIG. Note that this inclination angle is θ1=30 with respect to the X-axis, assuming that the X-axis and Y-axis (perpendicular to the plane of the paper) are horizontal to the focal point of the objective lens 1, and Z@ is perpendicular to the focal point. A range of '~60' was appropriate.

Next, after checking the presence and location of "dust" or "scratches" with the naked eye, in order to enlarge and observe this part with a microscope, the stage 10 is moved two-dimensionally and brought into focus of the objective lens 1. However, if the stroke is large, defocus will occur, so in order to correct this, a positioning mechanism 7 is provided to move the stage 10 in the vertical direction, that is, in the Z-axis direction.

By the way, the angle θ2 between the material surface and the optical axis of the tungsten lamp 8 is generally in the range of 0° to 45°.

Thus, according to this embodiment, the "
Inspection for dirt and scratches becomes significantly easier.

In the above embodiment, a tilting table 6 for tilting the entire microscope,
The principle of the positioning mechanism 7 that adjusts the vertical position of the stage 10 and the mounting position adjustment fitting 9 of the tungsten lamp 8 has been described above, so in reality, considering the adjustment range and accuracy, for example, the rack The present invention is not limited to this embodiment, and any suitable mechanism may be adopted, such as using a screw mechanism instead of a pinion.

(Effects of the Invention) As is clear from the above description, the present invention provides a microscope suitable for inspecting wafer pattern defects and mask defects, a tilting means for tilting the microscope at a predetermined angle, and It is equipped with a light source with an angle adjustment means for inspecting for defects and a position adjustment means for finely adjusting the stage for focusing in the vertical direction, so it can be used in conjunction with defect inspection of wafers and masks. This has the effect of making inspection for dirt and scratches extremely easy.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a conceptual diagram showing the configuration of a conventional semiconductor inspection microscope. 1... Objective lens, 2... Eyepiece lens, 3... Mirror, 4... Halogen lamp, 5... Adapter, 6
... Inclination table, 7 ... Positioning l [, 8 ... Tungsten lamp, 9 ... Position adjustment fitting, 1o ... Loading table. Applicant's agent Kiyoshi Inomata "IPJ20"

Claims (1)

[Claims] (1) The eyepiece lens is located at a position away from the direction in which the optical axis of the objective lens extends, and the object stage is capable of moving on the object surface in a direction orthogonal to the optical axis of the objective lens. a microscope comprising: a tilting means for tilting the entire microscope by a predetermined angle so that the eyepiece side of the object surface is the lowest with respect to the horizontal plane; and a reflecting surface perpendicular to the optical axis at the focal point of the objective lens. a light source having an angle adjustment means for reflecting the light directed toward the reflecting surface to a predetermined range near the eyepiece and adjusting an incident angle; 1. A microscope device for semiconductor inspection, comprising: position adjustment means for performing fine adjustment and focusing.