JPS5998532A - Preparation of reference defect sample - Google Patents

Abstract

PURPOSE:To make plural reference defects having various sizes by forming a flat on a sample and pressing a penetrator having a peaked end on plural positions of the flat with various pressure. CONSTITUTION:A plate sample 20 which is a silicon wafer having a main surface made to be a flat is put on an upper surface of a Y stage 3 with making an orientation flat plane 21 and X direction parallel. Adjustment is made so as to put a part 22 right under a penetrator 12 and as a sinker 13, what weighes W1 to form a pyramidal dent having a diagonal of 20mum is selected. When a cutout 16b of a cam becomes parallel to a sliding contact plane 14, a lever 7 rotates to lower the penetrator 12 in a direction of an arrow 24a thereby pressing the plate sample 20 by a predetermined pressure. When the weight of the sinker 13 decreases to W3, W4, W5 in turn, dents 26..., 27..., 28... having diagonals of 5mum, 2mum, 1mum respectively are formed by the similar process as for dents 23... and 25..., in a line on crossings of a lattice whose spaces are 10mm..

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a standard defect sample preparation method for making a standard defect sample used for calibration in an apparatus for detecting defects on semiconductor wafers.

[Technical background of the invention and its problems]

In the manufacturing process of semiconductor wafers (hereinafter simply referred to as wafers), dirt, dust, scratches, etc. on the wafers can cause product defects, so inspections for the presence of these items are strictly carried out in each process. has been done. In line with this, recently, surface defect detection apparatuses have been developed that mainly utilize light scattering by optical means and can perform this type of inspection automatically and quantitatively. Incidentally, such a surface defect detection device requires a standard defect sample for calibration. Therefore, standard defect samples for the above-mentioned calibration are currently being produced using various methods. For example, the most commonly used method is to spray standard size particles (polymer particles, trade name "Latex") on the surface of the surface. Further, as a method that requires a high level of technology, there is a method using a photoetching method to utilize a minute step on the convex surface of the sea urchin and use it as a standard defect. However,
In the case of a standard defect sample obtained by the method using the above standard particles,
It is not possible to arbitrarily control the position where the particles are dispersed, and it is extremely difficult to detect the position, and the results of inspecting the standard defect sample with an inspection device do not show whether it is due to standard particles or other dust, etc. It was not possible to determine whether it was caused by dust, etc. In addition, the standard defect sample produced by the photoetching method requires a resist cloth for forming the step, and special equipment for exposure and etching, which has the disadvantage that it is not possible to easily and inexpensively produce the standard sample. .

[Object of the invention]

The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a standard defect specimen manufacturing method that can easily and accurately form S quasi-defects at predetermined positions on a specimen.

[Summary of the invention]

After forming a flat portion on the sample, by pressing an indenter with a conical tip with various loads at multiple positions on the flat portion, a plurality of 41! It is designed to form semi-defects/defects.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail based on examples with reference to the present invention.

FIG. 1 shows a standard defect manufacturing apparatus used in the standard defect sample manufacturing method of this embodiment. The X stage (1) is provided so that it can be slightly moved in the X direction in the direction perpendicular to the plane of the paper in Figure 1 by rotating the knob (21) of the X micrometer (2) connected to the X stage (1). . On this X stage (1), the X stage (3) is moved as indicated by the arrow (5) in Figure 1 by turning the knob (4a) of the Y micrometer (4) connected to this X stage (3). It is mounted so that it can slide in the direction and move slightly.

The X stage (1) and the X stage (3) constitute a XX stage (6) which is a positioning mechanism.

On the other hand, above the XX stage (6) is a lever (7).
) is pivotally supported on the lever shaft (8), and arrows (9a), (9
b) It is rotatable in the direction. And lever (7
) is attached to one end of the support body a [. An indenter holder ←υ is provided on the lower surface of the support α.

An indenter a made of, for example, diamond and having a square pyramid-shaped tip is screwed onto the lower end of the indenter holder (1).

In addition, a cylindrical weight (13) is placed on the upper surface of the support α. (10a) to prevent it from falling or shifting its position.By arbitrarily setting the weight of this weight (131), the size of the indentation made by the indenter (a) can be adjusted. Furthermore, an engaging body u1 having a sliding surface I that is an inclined surface is attached to the other end of the lever (7).

The cam (
II is fixed to a rotating shaft (2) that rotates in the direction of the arrow by a rotational drive mechanism (not shown). The cam ul consists of a circumferential portion (16a) and a cutout portion (16b), and the cutout portion (16b) is a flat surface. Then, the cam 4 has a circumferential portion (16al) in contact with the sliding surface I.
lllllz When the lllllz sliding contact occurs, the l indenter 14 moves to the X stage (3
) is set so that it is spaced from the top surface. Therefore, when the cam u61 rotates and the cutout portion (16b) faces the sliding surface I, a gap is created between the two, and the lever (7)
rotates in the direction of arrow (9a), and the indenter α side descends. However, 13. The support body, the lever (force), the cam (1 [9, and the holding weight constitute the pressurizing mechanism 4).

Next, a standard defect manufacturing method using the standard defect sample manufacturing apparatus having the above configuration will be explained. First, X stage (3
A plate-shaped sample (
2) is placed so that the surface 01) of the cage 72 is parallel to the X direction. At this time, the relationship between the size of the indenter formed on the sample plate 1 and the weight of the main DQ31 is determined in advance.

Then, turn the respective knobs (2a) and (4m) of the Xl micrometer (2) and Y micrometer (4) to adjust the part (2nd stroke) directly below the indenter Q4 (see Figure 2). ).However, as the main D C1m,
Select a part (2) with a weight Wl that will form a square pyramid-shaped indentation with a diagonal length of 20 μm. At this time, move the circumferential part (16a) of the cam tte to the lever (force Keep the indenter (1) in contact with the sliding surface and separate it from the sample (2). Then, rotate the cam 4 in the direction of the arrow,
When the cutout part (16b) of the cam becomes parallel to the sliding surface I,
The lever (7) rotates in the direction of the arrow (9a), and accordingly, the indenter 0 descends in the direction of the arrow (24a), and the indenter housing presses the plate-shaped sample (to) with a predetermined load. Furthermore, the cam (1e) rotates and the circumferential portion (16Jl) changes to the sliding surface (1
4), the lever (7) rotates in the direction of the arrow (9b), and the indenter a4 rises in the direction of the arrow (24b) and returns to its home position. After the indenter [4 has been raised, an indentation is formed on the sample 4.

Next, turn the knob (4a) of the Y micrometer (4) to move the X stage (3) in the Y direction by 10 u, and do the same as before to set a square with a diagonal length of 20 pm. Pyramid-shaped indentations (0 rows) are formed in - rows at equal intervals of every 10 rows. Furthermore, the weight Wt (however, W2
< W + ) weight (131) and X
Rotate the knob (2a) of the micrometer (2) to
After moving the stage (1) in the X direction by 10 IllI, the X stage (3) is moved again in the Y direction by 10 IllI, and the impression c! In the same manner as J..., a quadrangular pyramid-shaped indentation Q [with] having a diagonal length of 10 μm is formed. Below, the weight of Omosu U31 is W3. W.

By gradually decreasing WI, the impression (c)...
, (2!19...), the length of the diagonal is
5 μm each.

2 μm, 1 μm indentation (a)..., @..., @...
. is formed in one row on the intersection points of the lattice with the lattice spacing lOIm. Indentations obtained in this way (c)...,Q...
..., cA..., (5)..., (c)... are standard defects used to calibrate a detection device that automatically detects defective areas such as dust, dirt, and scratches on semiconductor wafers. becomes.

Thus, according to this example, these indentations obtained on the 12th floor.
..., I251..., Qe..., (5)... are,
Since they are regularly arranged at predetermined positions, a required standard defect site can be easily identified, improving calibration efficiency and accuracy. Moreover, it has the advantage that it can be manufactured at a lower cost and more easily than a standard defect sample produced by photoetching.

In the above embodiment, the tip of the indenter (I) has a quadrangular pyramid shape, but it may have a conical shape.

Further, the standard defects are not limited to being arranged in a grid pattern as in the above embodiments, and in short, the standard defects may be formed radially as long as their positions can be specified. Alternatively, standard defects of different sizes may be formed at equal intervals simply on a straight line. Furthermore, in the above example, the sample is silicon immediately after final polishing.
Although a wafer is used, the surface condition of the wafer in each manufacturing process (film formation surface, pattern formed by etching, etc.) is the same as the surface condition of the wafer. If a standard defect is formed using the method of the present invention for the same phenol 1, the Gosho ellipse can be further improved.

〔Effect of the invention〕

The method for preparing a standard defect sample of the present invention is to press an indenter against the flat part of the sample with each residual load to obtain a standard defect that will serve as a calibration reference. and can be formed accurately. It also has the advantage that a standard defect sample can be produced easily and inexpensively without requiring a large-scale device. Moreover, since a required standard defect site can be easily specified, calibration efficiency and accuracy are improved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the standard defect sample preparation apparatus used in the standard defect sample preparation method of one embodiment of the present invention, and Fig. 2 is a standard defect sample preparation apparatus obtained by the standard defect sample preparation apparatus shown in Fig. 1. FIG. 3 is a plan view of a defective sample. Kan...sample, (L'lJ...indenter, (23),
(25), (26), (27), (28)...
- Indentation (standard defect). Agent: Patent attorney Noriyuki Chika (Oka or one other person)

Claims (1)

[Claims] forming a flat portion on the sample in which a standard defect is provided;
A method for forming a plurality of standard defects of different sizes by pressing an indenter with a conical tip against the sample using loads of different sizes at a plurality of positions on the flat part. Standard defect sample preparation method.